生物化学英文版练习题及答案。。。。精5则范文

第一篇：生物化学英文版练习题及答案。。。。精

Glossary for Biochemistry

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acetyl CoA carboxylase An enzyme that catalyzes the ATP-dependent synthesis of malonyl CoA from acetyl CoA and carbon dioxide, the committed step in fatty acid synthesis.acetylcholine A common neurotransmitter that exerts its effects by first binding to the acetylcholine receptor.acetylcholine receptor A ligand-gated channel that promotes a large inward current of sodium ions and triggers an action potential;composed of a pentamer of four kinds of polypeptide subunits, the channel opens to allow passage of sodium and potassium ions when two acetylcholine molecules promote transient opening of the channel.activated carriers Small molecules carrying activated functional groups that can be donated to other molecules;for instance, ATP carries activated phosphate groups and CoA carries activated acyl groups.activation domain The structural region of a transcription factor that facilitates transcription in some manner.See also DNA-binding domain.active site A specific region of an enzyme that binds the substrate and carries out catalysis.active transport The transport of an ion or a molecule against a concentration gradient, where DG for the transported species is positive;the process must be coupled to an input of free energy from a source such as ATP, an electrochemical gradient of Na+ or K+, or light.acyl adenylate A mixed anhydride in which the carboxyl group of a molecule is linked to the phosphoryl group of AMP;the formation of acyl adenylates is a means of activating carboxyl groups in biochemical reactions, such as the formation of fatty acyl CoA molecules from a free fatty acid and coenzyme A.acyl carrier protein(ACP)A bacterial polypeptide that is linked to phosphopantetheine and acts as a carrier of the growing fatty acyl chain during fatty acid biosynthesis.addition to or formation of double bond A reaction in which a functional group is added to a double bond or a group is removed from a molecule to form a double bond.adenylate cyclase An enzyme that generates cAMP, a second messenger, from ATP.adipocytes Mammalian cells that are the major storage site for triacylglycerols.aerobic glycolysis The use of lactic acid fermentation to generate ATP even the presence of enough oxygen to support cellular respiration.aerobic In the presence of oxygen.affinity chromatography A protein-purification technique based on the high affinity of many proteins for specific chemical groups.Such groups are attached to an inert matrix, and the protein sample is applied;only those proteins with an affinity for the groups will bind.affinity labeling A means of mapping the active site of an enzyme by using a substrate analog that binds to the active site and forms a covalent bond with a nearby amino acid.agonists Molecules that bind to receptor proteins and trigger signaling pathways.alcoholic fermentation The anaerobic conversion of glucose into ethanol with the concomitant production of ATP.aldolase An enzyme that cleaves an aldol.Aldolases are important in carbohydrate metabolism.aldose A monosaccharide whose C-1 carbon atom contains an aldehyde group.allosteric interaction An interaction between a small molecule(a ligand)and a site on a protein that may be some distance away from the active site;the interaction causes a conformational change and consequent alteration in the catalytic activity of the protein.α helix A common structural motif in proteins, in which a polypeptide main chain forms the inner part of a right-handed helix, with the side chains extending outward;the helix is stabilized by intrachain hydrogen bonds between NH and CO groups of the main chain.α-ketoglutarate dehydrogenase A citric acid cycle enzyme that catalyzes the oxidative decarboxylation of α-ketoglutarate to yield succinyl CoA.This enzyme, which helps to regulate the rate of the citric acid cycle, is structurally and mechanistically similar to the pyruvate dehydrogenase complex.α-amylase A hydrolytic enzyme that cleaves the a-1,4 bonds of starch and glycogen, but not the a-1,6 bonds.Ames test A simple, rapid means of detecting carcinogens by measuring a chemical's ability to induce mutations in Salmonella bacteria.amiloride-sensitive sodium channel A sodium channel important in the detection of the taste of salt.Such channels are inhibited by amiloride, which also mutes the taste of salt.amino acid An organic acid with an α-carbon atom linked to a carboxylic acid, an amino group, a hydrogen atom, and a side chain(the R group).Twenty different amino acids are the building blocks of proteins.amino sugar A sugar that contains an amino group rather than a hydroxyl group at the C-2 position;the most common amino sugars are glucosamine and galactosamine.aminoacyl-tRNA An amino acid ester of transfer RNA.aminoacyl-tRNA synthetase An enzyme that activates an amino acid and then links it to transfer RNA.Also known as an activating enzyme, each aminoacyl-tRNA synthetase is specific for a particular amino acid.aminotransferase(transaminase)A class of enzymes that transfer an α-amino group from an α-amino acid to an α-keto acid.Also called transaminases.ampere A measure of electrical current: the flow of 6.24 × 1018 charges per second.amphipathic molecule A molecule, such as a membrane lipid, that contains both a hydrophobic and a hydrophilic moiety.amylopectin The branched form of starch, containing glucose residues in about one α-1,6 linkage per thirty α-1,4 linkages.amylose The unbranched form of starch, containing glucose residues in α-1,4 linkage.anabolism The set of metabolic reactions that require energy to syntheize molecules from simpler precursors.anaerobic In the absence of oxygen.anaplerotic reaction From the Greek for “fill up,” referring to a reaction that replenishes intermediates removed from a metabolic pathway.The most common example is the reaction catalyzed by pyruvate carboxylase, in which the carboxylation of pyruvate produces oxaloacetate, a key component of the citric acid cycle.anion exchange Ion-exchange chromatography in which a protein mixture is passed through a column containing a matrix bearing positive charges.Proteins bearing negative charges will bind to the column while those with positive charges will pass through the column.anomers Isomers of cyclic hemiacetals or hemiketals, with different configurations only at the carbonyl carbon atom;that carbon is known as the anomeric carbon.2 antagonist A molecule that binds to a receptor protein but does not trigger the signaling pathway.Such molecules are like competitive inhibitors for enzymes.antibody A protein synthesized by an animal in response to the presence of a foreign substance, or antigen;often binds to the antigen, neutralizing it or marking it for destruction.anticodon Three-nucleotide sequence of tRNA that base-pairs with a codon in mRNA.antigen A foreign substance that elicits the synthesis of an antibody.antigenic determinant Site on an antigen to which an antibody binds.Also called an epitope.antigenic determinant The specific site on an antigen that is recognized by an antibody.Also known as an epitope.antimycin A An antibiotic from Streptomyces that inhibits the respiratory chain by blocking electron transfer in the cytochrome reductase complex.antiserum Serum prepared from the blood of an immunized animal containing soluble antibodies specific for a particular antigen.apoptosis A cascade of proteolytic enzymes that results in controlled cell death in response to significant cell damage or specific developmental programs.Also called programmed cell death.Archaea The domain of life that comprises single cell organisms lacking a nucleus.Formerly believed to be member of the domain Bacteria, Archaea are now known to have a unique evolutionary history with biochemical characteristics different from the other two domains of life.ascorbate(vitamin C)A water-soluble vitamin that functions as an antioxidant and is required for the hydroxylation of collagen;scurvy results if ascorbate is deficient.assay A test for some unique identifying property of a protein to be purified.ATP(adenosine 5'-triphosphate)A nucleotide consisting of adenine, ribose, and triphosphate units that serves as the cellular energy currency.ATP synthase Molecular assembly of the inner mitochondrial membrane responsible for the respiratory-chain-driven synthesis of ATP.Also called Complex V, mitochondrial ATPase, H+-ATPase, or F0F1-ATPase.ATPase Enzymes that catalyze the hydrolysis of adenosine triphosphate(ATP)to form adenosine diphosphate(ADP)and inorganic phosphate(Pi)and use the energy released to power otherwise endergonic reactions.ATP-driven pump Membrane proteins that use the energy of ATP hydrolysis to drive the thermodynamically uphill transport of ions or molecules.autoradiography A means of detecting radioactive molecules immobilized in a separation medium such as polyacrylamide;the radioactivity of the molecules will blacken x-ray film.B

Bacteria The domain of life that comprises single cell organisms lacking a nucleus.Members of this domain differ evolutionarily and biochemically from the Archaea, with whom they were formerly grouped.bacterial artificial chromosome An artificial bacterial chromosome, a highly engineered version of the E.coli fertility(F factor), that can serve as a cloning vector for inserts as larges as 300 kb.bacteriorhodopsin A 26-kd integral membrane protein that absorbs light and converts its energy into proton-motive force, which is then used to synthesize ATP.3 ball-and-chain model A model for the regulation of the K channel that postulates that the first +20 residues of the K channel form a cytoplasmic unit(the ball)that is attached to a flexible segment of the polypeptide(the chain).When the channel is closed, the ball rotates freely in the aqueous solution.When the channel opens, the ball quickly finds a complementary site in the open pore and occludes it.basic-leucine zipper(bZip)protein A eukaryotic DNA binding unit that consists of a pair of long  helices.Because these pairs are often stabilized by appropriately spaced leucine residues, these structures are often referred to as leucine zippers.B-DNA helix A right-handed double helix with the following characteristics: the two strands are antiparallel;the bases are inside the helix and the phosphates and deoxyribose sugars are on the outside;adenine forms hydrogen bonds with thymine, and guanine forms them with cytosine;the bases in each pair are coplanar;there are 10.4 residues per turn, with a pitch of 35 Å.β sheet A common structural motif in proteins, in which two or more β strands are associated as stacks of chains, stabilized by interchain hydrogen bonds;a number of β strands running in the same direction form a β pleated sheet, whereas such strands running in opposite directions form an antiparallel pleated sheet.β-galactosidase An essential enzyme in lactose metabolism that hydrolyzes lactose into galactose and glucose.bifunctional enzyme An enzyme with two different, often opposing, catalytic activities on one polypeptide chain.For instance, phosphofructokinase 2 synthesizes fructose 2,6-bisphosphate and fructose 2,6-bisphosphatase hydrolyzes it, yet both active sites are on the same polypeptide chain.bile salts Polar derivatives of cholesterol that are made in the liver, stored in the gall bladder, and released into the small intestine, where they act as detergents to solubilize dietary lipids, facilitating their digestion and absorption.biological macromolecule

Large molecules such as proteins and nucleic acids, that are key functional and structural components of living systems.biotin A vitamin that plays a role in carboxylation and decarboxylation reactions.2,3-bisphosphoglycerate An allosteric effector of hemoglobin that decreases the affinity of hemoglobin for oxygen.blood–brain barrier The tight junctions between endothelial cells that line blood vessels within the brain and spinal cord.body mass index(BMI)A value, calculated by dividing a person’s weight in pounds(kg)by 2(height in inches(cm)), that is a reliable indicator of obesity for most people.Bohr effect The observation made by Christian Bohr that H+ and CO2 promote the release of oxygen from oxyhemoglobin.bongkrekic acid An antibiotic that inhibits the action of ATP-ADP translocase.buffer An aqueous solution consisting of a weak acid and it conjugate base(or vice versa)that resists changes in pH when strong acids or bases are added.+

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C3 plant A plants that lacks the C4 pathway.C4 pathway A means by which four-carbon compounds, such as oxaloacetate and malate, carry carbon dioxide from mesophyll cells in contact with the air to bundle-sheath cells, which are the 4 major sites of photosynthesis.The pathway accelerates photosynthesis by concentrating carbon dioxide in photosynthetic cells.C4 plant A plant that utilizes the C4 pathway.CAAT box A component of many eukaryotic promoters with the consensus sequence 5'-GNCAATCT-3'.calorie The amount of heat required to raise the temperature of 1 gram of water from 14.5°C to 15.5°C.Calvin cycle(Dark reactions)In plants, a cyclic metabolic pathway in which carbon dioxide is incorporated into ribulose 1,5-bisphosphate to give compounds that can be used for the synthesis of glucose.5' cap A structure at the 5' end of eukaryotic mRNA that stabilizes the mRNA and enhances its translation.The cap contains a 7-methyl guanylate residue attached by a triphosphate linkage to the sugar at the 5' end of the mRNA in a rare 5'-5' linkage.carbohydrates Saccharides, which are aldehyde or ketone compounds with multiple hydroxyl groups.Also defined as organic compounds with the empirical formula(CH2O)n.carbon monoxide CO;A colorless, odorless gas that binds to hemoglobin at the same site as oxygen and thereby prevents oxygen binding.carbonic anhydrase An enzyme that catalyzes the reaction of carbon dioxide with water to form carbonic acid.carbonium ion A carbon compound that contains a positively charged carbon atom;a carbonium atom is critical for catalysis by lysozyme

carboxyhemoglobin A complex of carbon monoxide and hemoglobin that does not bind oxygen.carboxylase An enzyme that catalyzes a carboxyl transfer reaction;biotin is usually required as a coenzyme.carnitine A zwitterionic compound formed from lysine that acts as a carrier of long-chain fatty acids from the cytosol to the mitochondrial matrix.cascade, enzymatic A sequence of reactions, in which at each step a product stimulates an ensuing reaction, generating an amplification of a relatively small stimulus or signal.catabolism The set of metabolic reactions that transform fuels into cellular energy.catabolite activator protein(CAP)The cAMP response protein;when bound to cAMP, CAP binds to an inverted repeated of the lac operon, near position-61 relative to the start site of transcription, to stimulate transcription.catabolite repression The repression by glucose of catabolic enzymes required for the catabolism of carbohydrates other than glucose.catalase A ubiquitous heme protein that catalyzes the dismutation of hydrogen peroxide into molecular oxygen and water.catalysis by approximation Enhancing the rate of a reaction by bringing multiple substrates together along a single binding surface of an enzyme.catalytic antibodies Antibodies generated by using transition-state analogs of a particular reaction as antigens.Such antibodies often function as catalysts for the reaction.Also called abzymes.catalytic group An amino acid or cofactor at an enzymes active site that directly participates in the making or breaking of covalent bonds.catalytic RNA One of a class of RNA molecules that display enzymatic activity.5 catalytic triad A constellation of three residues, found in many proteolytic enzymes, in which two of the residues convert the remaining residue, usually a serine or cysteine, into a potent nucleophile.cation exchange Ion-exchange chromatography in which a protein mixture is passed through a column containing a matrix bearing negative charges.Proteins bearing positive charges will bind to the column while those with negative charges will pass through the column.CD4 A protein present on the surface of helper T cells that, along with the T-cell receptor, binds to class II MHC proteins on antigen-presenting cells.CD4 is the source of the specificity of helper T cells for class II MHC interactions.cDNA library A collection of all of the complementary DNA for all mRNA that a cell contains, which have been inserted into vectors, and then inserted into bacteria.CDP-alcohol Activated form of an alcohol that can be used in the synthesis of phosphoglycerides by combining with diacylglycerol at the free hydroxyl group on glycerol;for instance, CDP-choline can react with diacylglycerol to form the phospholipid phosphatidylcholine.CDP-diacylglycerol(cytidine diphosphodiacylglycerol)Formed from phosphatidate and cytidine triphosphate(CTP);activated diacylglycerol used in the synthesis of phosphoglycerides such as phosphatidyl serine.cell cycle The coordination of DNA replication and cell division in eukaryotes.Mitosis takes place only after DNA synthesis.Two gaps(G1 and G2)in time separate the two processes.cellular respiration The generation of high-transfer-potential electrons by the citric acid cycle, their flow through the respiratory chain to O2, and the accompanying synthesis of ATP.cellulose An unbranched homopolysaccharide in plants, composed of glucose residues in α-1,4 linkage;the major structural polysaccharide in plants.ceramide(N-acyl sphingosine)A sphingosine with a long-chain acyl group attached to the amino group.cerebroside A sphingolipid in which glucose or galactose is linked to the terminal hydroxyl group of a ceramide.cGMP phosphodiesterase An enzyme that hydrolyzes cyclic GMP to GMP;in the visual system, this hydrolysis leads to the generation of an action potential. chain One of the protein subunits of hemoglobin.Hemoglobin is composed of two  chains and two  chains. chain One of the protein subunits of hemoglobin.Hemoglobin is composed of two  chains and two  chains.channel A protein passage that is continuous and that allows ions to flow rapidly through a eukaryotic membrane from a compartment of higher to a compartment of lower concentration.Channels(also known as pores in bacteria)are generally composed of four to six subunits, or domains, and are gated by membrane potential, allosteric effectors, or covalent modification.channel Membrane proteins that provide a pore through which ions can flow very rapidly in a thermodynamically downhill direction.chaperone proteins Slow ATPases that bind newly synthesized proteins and assist their proper folding.chemical modification reaction A reaction in which a molecule modifies a specific amino acid residue in a protein.6 chemiosmotic hypothesis The idea that electron transfer in the respiratory chain is used to pump protons across the inner mitochondrial membrane, establishing a proton gradient;this gradient(the proton-motive force)drives the synthesis of ATP by ATP synthase.chitin A glycosaminoglycan found in the exoskeleton of insects, crustaceans, and arachnids and is, next to cellulose, the second most abundant polysaccharide in nature.chloroplast The plant organelle in which photosynthesis takes place.cholesterol A sterol that is an important constituent of eukaryotic membranes as well as lipoproteins;also a precursor of steroid hormones.chromatin immunoprecipitation(ChIP)A technique for identifying the binding sites of DNAbinding proteins.The protein is cross-linked to DNA to which it is bound in chromatin, and the DNA is fragmented into small pieces.Antibodies to the bound protein are used to isolate the chromatin fragments with the bound protein.The cross-linking is reversed, and the DNA is isolated and characterized.chromatin Nucleoprotein chromosomal material consisting mainly of DNA and histones.chylomicrons Lipoprotein particles that transport dietary triacylglycerols from the intestine to other tissues;apolipoprotein B-48 is a protein component of chylomicrons.citrate synthase An enzyme that catalyzes the condensation of acetyl CoA with oxaloacetate to form citrate, initiating the citric acid cycle.citric acid cycle A cyclic series of metabolic reactions that completely oxidize acetyl units to carbon dioxide.Also known as the tricarboxylic acid cycle(after citrate)or the Krebs cycle, after Hans Krebs, who elucidated the cyclic nature of the pathway.coactivator Proteins that activate transcription by binding to specific transcription factors and then catalytically modifying chromatin components.cobalamin(vitamin B12)A complex taking part in a number of reactions including the formation of deoxyribonucleosides from ribonucleosides.coding strand The strand of DNA that has the same sequence as the RNA transcript except it contains thymine(T)in place of uracil(U).codon Nucleotide triplet in mRNA that encodes for a particular amino acid.coenzyme A(CoA)A coenzyme consisting of an adenine nucleotide linked to pantothenate, which is itself linked to mercaptoethylamine;universal carrier of acyl groups, which are bound to the mercaptoethylamine unit.coenzyme A small organic molecule required for the activity of many enzymes;vitamins are often components of coenzymes.coenzyme Q A mobile electron carrier that is a component of the respiratory chain;it shuttles between the oxidized ubiquinone form to the reduced ubiquinol form through a semiquinone intermediate;accepts electrons from NADH-Q reductase as well as succinate-Q reductase.cofactors Small molecules, such as metals or coenzymes, that many enzymes require for catalytic activity.cohesive ends In double-stranded DNA molecules, complementary single-stranded ends produced by staggered cuts.Specific cohesive ends in DNA can be produced by certain restriction enzymes, such as EcoRI, and can then be used to join unrelated DNA molecules by annealing and joining with DNA ligase.collagen The main fibrous protein component of skin, bone, tendon, cartilage, and teeth;the collagen helix contains three helical polypeptide chains, each nearly 1000 residues long.Glycine appears at every third residue in the amino acid sequence, and the sequence glycine-proline-hydroxyproline recurs frequently.committed step The first irreversible step in a metabolic pathway under physiologic conditions;this step is catalyzed by an allosteric enzyme and commits the product to a particular chemical fate.competitive inhibition The reduction in the rate of enzyme activity observed when the enzyme can bind the substrate or the inhibitor but not both.Many competitive inhibitors resemble the substrate and compete with it for binding to the active site.Relief from inhibition by saturation with substrate is a kinetic hallmark of competitive inhibition.complementary DNA(cDNA)DNA complementary to an mRNA sequence.concerted mechanism A model explaining the kinetics of allosteric enzymes in which the transitions of all of the active sites between the T state and the R state occur simultaneously.consensus sequence Idealized base sequence that represents common features of a promoter site.conservative substitutions Mutations that replace one amino acid with another similar in size and chemical properties.constitutive genes Genes that are not subject to regulation and are constantly transcribed.convergent evolution The acquisition of similar structure to perform a similar biochemical activity in proteins that have evolved independently.convergent evolution The process by which different evolutionary pathways arrive at the same solution to a biochemical problem.cooperative A property of allosteric proteins wherein the reactions at different sites are not independent of one another.cooperativity A property of many allosteric enzymes in which the binding of substrate to one active site favors the transition of all active sites from the T state to the R state, leading to an increase in enzyme activity.core glycosylation The addition of carbohydrates to proteins and the processing of these carbohydrates that takes place in the endoplasmic reticulum.corepressor A small molecule that binds to a repressor protein;the corepressor-repressor complex then binds to the operator DNA of a particular operon to inhibit transcription.Cori cycle A cyclic metabolic pathway in which lactate from active muscle is converted into glucose by the liver, which in turn supplies newly synthesized glucose to muscle and other tissues.Cori disease A disease in which the structure of liver and muscle glycogen is abnormal and the amount is increased;it is due to an inability to hydrolyze the α-1,6-glycosidic bonds in glycogen;liver function is compromised.cotransporter Transporters that couple the thermodynamically unfavorable flow of one species of ion or molecule up a concentration gradient to the favorable flow of a different species down a concentration gradient.covalent bond A chemical bond formed by the sharing of pairs of electrons between adjacent atoms.Covalent bonds are the strongest chemical bonds.covalent catalysis Catalysis in which the active site contains a reactive group that becomes temporarily covalently modified in the course of catalysis.covalent intermediate In a catalytic mechanism, an intermediate comprising a component of the substrate covalently bound to the enzyme.covalent modification The attachment to and removal of chemical groups from an enzyme and the consequent change in the catalytic properties of that enzyme.Catalytic properties of many enzymes are altered by the covalent attachment and removal of phosphoryl groups, whereas a smaller number of others undergo reversible attachment of AMP units from ATP.CpG islands Regions of DNA rich in the sequence CpG, usually located at the 5' region of genes;the cytosine bases of these islands can be methylated to inhibit transcription of the associated gene.creatine phosphate(phosphocreatine)In muscle, a compound with a high phosphoryl transfer potential that is used to regenerate ATP from ADP during the initial seconds of muscle contraction.cross talk Interactions between several signaling pathways.Cross talk permits more finely tuned regulation of cell activity than would the action of individual independent pathways.cyclic AMP(cyclic 3', 5'-adenosine monophosphate)A cyclic nucleotide formed from ATP and an important second messenger in a variety of signaling systems.cyclic GMP(cyclic 3', 5'-guanosine monophosphate)A cyclic nucleotide formed from GTP and an important second messenger in vision.cytochrome An electron-transferring protein that contains a heme prosthetic group whose iron component shuttles between the ferrous(+2)and ferric(+3)state during electron transfer.cytochrome c A water-soluble, highly conserved cytochrome component of the respiratory chain that accepts electrons from cytochrome reductase and is in turn oxidized by cytochrome oxidase.cytochrome c oxidase The final complex of the respiratory chain, cytochrome c oxidase transfers electrons from cytochrome c to molecular oxygen and concomitantly pumps protons across the inner mitochondrial membrane to generate the proton-motive force.Also called Complex IV.cytochrome P450 monooxygenase A family of mixed function oxygenases that add OH groups to various biochemicals, including steroid hormones.These enzymes require NADPH, O2 and cytochrome P450.cytochrome P450 system Found in adrenal mitochondria and liver microsomes, an electron-transport chain in which the terminal component is cytochrome P450;this system plays a role in the detoxification of foreign substances by altering them to increase their solubility and facilitate excretion.cytoskeleton Internal scaffolding of cells, made up of microfilaments, intermediate filaments, and microtubules, which enables cells to transport vesicles, change shape, and migrate.D

dalton A unit of mass very nearly equal to that of a hydrogen ion and precisely equal to 1.000 on the atomic mass scale.dark reactions In chloroplasts, the reactions in which carbon dioxide is fixed into organic compounds, driven by ATP and NADPH.de novo pathway A biosynthetic pathway that builds the final product from simple precursors.See also salvage pathway.decarboxylase An enzyme that removes a carbon atom from a substrate in the form of carbon dioxide.denaturation A disruption in the native conformation of a macromolecule that causes a loss of normal function.deoxyhemoglobin A conformation of hemoglobin that is unable to bind oxygen.Also called the T or tense form.deoxynucleotide A nucleotide containing a purine or pyrimidine base covalently linked to 2-deoxyribose, which is in turn linked to one or more phosphate groups.deoxyribose A five-carbon monosaccharide(C5H9O5)that constitutes the carbohydrate moiety of a deoxynucleotide;the deoxyribose commonly found in deoxynucleotides is 2-deoxyribose.diabetes A disease characterized by the overproduction of glucose by the liver and its underutilization by other organs.Type I diabetes is due to an insufficiency of insulin production, whereas type II is due to the inability of insulin receptors to respond to the hormone.diacylglycerol A second messenger in the phosphoinositide cascade, which leads to the activation of protein kinase C.dialysis The process of removing small molecules from a solution containing a mixture of large molecules and small molecules.The mixture is placed in a bag made of a semipermeable membrane, which is then placed in a different solution.The membrane allows escape by the small molecules but not the large molecules.diastereoisomers A pair of molecules, each with more than one asymmetric center, that have opposite configurations at one such center but are not mirror images of each other;in the aldotetrose series, Derythrose and D-threose are diastereoisomers. dimer A pair of subunits(11and22 that comprise the functional unit of hemoglobin.dimerization arm A molecular structure on the EGF receptor that is exposed only upon binding EGF and that subsequently reaches out and inserts into a binding pocket on another EGF receptor monomer, facilitating dimerization.direct repair A means of repairing damaged DNA in which the damaged region is corrected in place.For example, pyrimidine dimers are simply cleaved to restore the original nucleotides.dismutase An enzyme that catalyzes a dismutation reaction in which a single reactant is converted into two different products.dissociation constant(Kd)A measure of strength of the interaction of a ligand for a receptor defined by the expression Kd = [R] [L]/[RL] where [R] is the concentration of the free receptor, [L] is the concentration of the free ligand, and [RL] is the concentration of the receptor–ligand complex.distal histidine A histidine in globins that forms a hydrogen bond to the bound oxygen that helps to prevent the release of superoxide anion.disulfide bond A covalent bond formed by the oxidation of two sulfhydryl groups;the oxidation of cysteine residues in a polypeptide yields a disulfide bond linking the two residues.divergent evolution The evolutionary process by which proteins with different properties are derived from a common ancestor.DNA ligase An enzyme that catalyzes the formation of a phosphodiester bond between the 3'-OH group at the end of one DNA chain and the 5'-phosphate group at the end of the other chain;it takes part in the synthesis, repair, and splicing of DNA.DNA microarray(gene chip)A solid support such as a microscope slide to which are affixed oligonucleotides or cDNAs corresponding to specific genes.Fluorescently labeled cDNA is hybridized to the slide to reveal the expression level for each gene, identifiable by its known position within the microarray.DNA polymerases Enzymes that catalyze the template-directed, primer-dependent addition of deoxynucleotide units, using deoxynucleotide triphosphates as substrates, to the 3' end of a DNA chain;chain growth is in the 5'-to 3'-direction;such enzymes replicate and repair DNA.DNA probe A radioactively labeled, single-stranded specific base sequence used to locate a complementary sequence among DNA fragments displayed on an electrophoretic gel.DNA-binding domain The structural region of a transcription factor that recognizes and binds to a particular DNA sequence.See also activation domain.dolichol phosphate A lipid, residing in the ER membrane, containing approximately 20 isoprene units that serves as a carrier of oligosaccharides destined to be attached to a protein.domain An independently folded unit in the tertiary structure of a polypeptide chain;may contain a number of supersecondary structures.In multienzyme complexes, each domain may carry out one or more catalytic reactions.In proteins, a compact globular unit of 100 to 400 residues, possibly joined to other domains by a flexible polypeptide segment;often encoded by a specific exon in the gene encoding the protein.E

Edman degradation The sequential removal of the N-terminal amino acid from a protein as a phenylthiohydantoin derivative;used in sequencing proteins.EGF receptor(EFGR)A receptor tyrosine kinase that is activated by epidermal growth factor.The unbound receptor exists as a monomer, but dimerizes upon growth factor binding.eicosanoid A carbon compound containing 20 carbon atoms;prostaglandins are examples.Eicosanoids often act as local hormones.electrochemical potential(membrane potential)A thermodynamic measure of the energy resulting from an unequal distribution of a population of molecules across a membrane that takes in account concentration differences and charge differences between the two sides of the membrane.electrophoresis A technique used to separate charged molecules, such as proteins and nucleic acids, that is based on the fact that such molecules will move at differing rates in an electric field, depending on factors such as net charge, size, and shape of the molecules.electrostatic interaction A bond formed when a charged group on one molecule attracts an oppositely charged group on another molecule.Embden-Meyerhof pathway Glycolysis.enantiomers A pair of molecules, each with one or more chiral centers, that are mirror images of each other.endoplasmic reticulum(ER)An extensive system of cytoplasmic membranes that comprises about half the total cell membrane.The region of the ER that binds ribosomes is called the rough ER, and the region that is devoid of ribosomes is called the smooth ER.enhancers DNA sequences that have no promoter activity themselves but that can greatly enhance the activity of other promoters;enhancers can exert their stimulatory effect over a distance of several thousand nucleotides.entropy A measure of the degree of randomness or disorder in a system;denoted by the symbol S in thermodynamics, the change in entropy(.S)increases when a system becomes more disordered and decreases when the system becomes more ordered, or less random.enzyme multiplicity A regulatory strategy in which the committed step common to several pathways is catalyzed by different enzymes with the same catalytic properties but different regulatory properties.Each enzyme thus responds to the final product of one of the pathways having the committed step in common.enzyme-linked immunoabsorbant assay(ELISA)An assay for quantifying the presence of an antigen by using an enzyme linked to an antibody to the antigen.enzymes Biological macromolecules that act as catalysts for biochemical reactions;although almost all are composed of protein, catalytically active RNA molecules have been recently discovered.enzyme-substrate complex The product of specific binding between the active site of an enzyme and the substrate.epimerases Enzymes that catalyze the interconversion of epimers of a compound.epimers Pairs of molecules, each with more than one asymmetric center, that differ in configuration at only one such center;glucose and galactose are epimers, differing only in the configuration at C-4.epinephrine(adrenaline)A catecholamine released by the adrenal medulla in response to muscle activity or its anticipation that stimulates the breakdown of muscle glycogen.epitope The specific site on an antigen that is recognized by an antibody.Also known as the antigenic determinant.equilibrium potential The equilibrium achieved when the driving force due to a concentration gradient is balanced by an electrostatic force resisting the motion of additional charges;applies to a membrane separating two different concentrations of ion with a channel connecting the two sides of the membrane.ER(endoplasmic reticulum)stress The inability of the endoplasmic reticulum of -cells of the pancreas to process all of the proinsulin and insulin.ER stress is a precursor to pancreatic failure.erythromycin An antibiotic that binds to the 50S ribosomal subunit and inhibits peptide translocation in prokaryotes.erythropoietin(EPO)A glycoprotein hormone secreted by the kidneys that stimulates the production of red blood cells.essential amino acids Amino acids that cannot be synthesized de novo and therefore must be acquired from the diet;in adult mammals, at least nine amino acids are considered essential.eukaryote A member of the domain Eukarya.The defining characteristic of eukaryotes is the presence of a well-defined nucleus within each cell.evolutionary tree A branching diagram or ―tree‖ that shows the evolutionary relatedness of different organisms on the basis of some biological characteristic, such as the amino acid sequences of a family of proteins.exons Regions of pre-mRNA that are retained in mature mRNA.exonuclease An enzyme that digests nucleic acids from the ends of the molecule, rather than at an internal site;exonucleases can be specific for digestion from the 3' or 5' ends of the nucleic acid.expression vector A plasmid-cloning vector that has been optimized for the expression of large amounts of recombinant protein encoded by the vector.F

Fab fragment One of two 50-kd polypeptide chains produced when immunoglobulin G is cleaved by the protease papain;Fab fragments bind antigens but cannot cross-link them, because each fragment has only one binding site for an antigen.facilitated diffusion Transport of an ion or a molecule down a concentration gradient, where.G for the transported species is negative.Also called passive transport.FAD and FADH2(flavin adenine dinucleotide)An important electron carrier in the oxidation of fuel molecules;alternates between the oxidized FAD form and the reduced FADH2 form.It consists of a flavin moiety and an AMP unit;electrons are carried on the isoalloxazine moiety of the molecule.12 familial hypercholesterolemia A disease that results from the dysfunctional receptor-mediated endocytosis of cholesterol-bearing lipoprotein particles.With this disease, patients have abnormally high blood levels of cholesterol, which can lead to arterial narrowing and heart attacks at an early age.fatty acid synthase An enzyme system that catalyzes the synthesis of saturated long-chain fatty acids from acetyl CoA, malonyl CoA, and NADPH;in bacteria, the constituent enzymes of the synthase complex can be dissociated when cell extracts are prepared;in mammals, all constituent enzyme activities in fatty acid synthase are part of the same polypeptide.fatty acids Carboxylic acids containing long hydrocarbon chains that are an important fuel source as well as a key component of membrane lipids.Fc fragment One of two 50-kd polypeptide chains produced when immunoglobulin G(IgG)is cleaved by the protease papain;the Fc fragment of an intact IgG molecule cannot participate in antigen binding but can mediate other important biological activities, such as complement fixation.feedback inhibition A mode of enzyme regulation in which the end product of a biosynthetic pathway inhibits the enzyme that catalyzes the first step in that pathway.feedforward stimulation The activation of an allosteric enzyme in a later stage of a pathway by the product of a reaction that takes place earlier in the reaction pathway.fermentation An ATP-generating process in which organic compounds act as both donors and acceptors of electrons;fermentations can take place in the absence of oxygen.ferredoxin The penultimate electron acceptor in photosystem I.Reduced ferredoxin

+subsequently reduces NADP to NADPH.ferrihemoglobin Hemoglobin in which the iron component of the heme prosthetic group is in the ferric(+3)state;ferrihemoglobin cannot bind oxygen.first messengers Hormones;molecules that transduce signals from one tissue to another tissue(the target tissue)through the blood.Fischer projection A means of depicting the stereochemistry of a molecule.In a Fischer projection of a molecule, atoms joined to an asymmetric carbon atom by horizontal bonds are in front of the plane of the page, and those joined by vertical bonds are behind.flavin mononucleotide(FMN)A coenzyme for oxidation-reduction reactions derived from the vitamin riboflavin.The electron acceptor of FMN, the isoalloxazine ring, is identical with that of FAD, but FMN lacks the adenyl nucleotide component of FAD.flavins Electron carriers that use riboflavin in electron-transfer reactions;FAD, FADH2, FMN, and FMNH2 are flavins.flavoproteins Proteins tightly associated with FAD or FMN;flavoproteins play important roles in many oxidation-reduction reactions.fluid mosaic model The description of membranes as two-dimensional solutions of oriented lipids and globular proteins.folding funnel A depiction of the thermodynamics of protein folding.The top of the funnel represents all possible denatured conformations—that is, maximal conformational entropy.Depressions on the sides of the funnel represent semistable intermediates that can facilitate or hinder the formation of the native structure, which is at the very bottom of the funnel.fractional saturation The fraction of possible binding sites of a biomolecule that are occupied.free energy A form of energy capable of doing work under conditions of constant temperature and pressure.Also, a measure of the usable energy generated in a chemical reaction;denoted by the symbol G in thermodynamics.The change in free energy(.G)of a system undergoing transformation at constant pressure is equal to the change in enthalpy(.H)minus the product of the absolute temperature(T)and the change in entropy(.S).furanose A five-membered heterocyclic ring formed when a monosaccharide cyclizes to form a hemiacetal or a hemiketal;the five-membered oxygen-containing ring is similar to that of furan.G

G protein A guanyl nucleotide-binding protein that is a component of intracellular signaling pathways.In the inactive state, the G protein(sometimes called a heterotrimeric G protein)is a trimeric protein consisting of αβã subunits, with the GDP bound to the α subunit.In the active state, the α protein exchanges GDP for GTP and dissociates from the βã subunits.The GTP-bound α subunit propagates the signal.Signal propagation is terminated when the α subunit hydrolyzes GTP to GDP and reassociates with the βã subunits.β-galactosidase In lactose metabolism, an essential enzyme that hydrolyzes lactose into galactose and glucose.ganglioside A ceramide, common in membranes of the nervous system, in which an oligosaccharide is linked to the ceramide by a glucose residue.gap junctions Passageways between the interiors of two contiguous cells.Also known as cell-to-cell channels.GC box A component of many eukaryotic promoters, especially those from constitutively expressed genes.The consensus sequence for the GC box is 5'-GGGCGG-3'.gel electrophoresis A technique used to separate charged molecules, such as proteins and nucleic acids, which is based on the fact that such molecules will move at differing rates through a gelatinous material, such as polyacrylamide or agarose, when subjected to an electric field.Separation depends on factors such as net charge, size, and shape of the molecules.gel-filtration chromatography A separation technique based on size differences.A sample is applied to a column consisting of porous beads.Large molecules move through the column faster than small molecules because they cannot enter the beads and, thus, have a shorter path to travel.gene duplication Duplication of a gene in the process of replication.One of the duplication products may accumulate mutations and eventually evolve into a gene with a different but related function.general acid catalysis Acid catalysis in which the source of the proton is a donor group rather than a free H+.general acid-base catalysis Catalysis in which a molecule other than water plays the role of a proton donor or acceptor.genetic code The relation between nucleic acid sequence information and protein sequence information.genomic library A collection of DNA fragments, inserted into vector molecules, that represents the entire genome of an organism.glucagon A polypeptide hormone that is secreted by the α cells of the pancreas when the bloodglucose level is low and leads to glycogen breakdown in the liver and the release of glucose to the blood.glucogenic amino acid An amino acid whose carbon skeleton, entirely or in part, can be converted into substrates for gluconeogenesis.gluconeogenesis The synthesis of glucose from noncarbohydrate precursors, including lactate, glycerol, and amino acids.glucose 6-phosphatase A membrane protein of the lumenal side of the endoplasmic reticulum that catalyzes the formation of free glucose from glucose 6-phosphate.In the liver, the enzyme plays a key role in maintaining blood-glucose levels.glucose 6-phosphate A key intermediate in metabolism that can be processed to free glucose, stored as glycogen, oxidized to produce NADPH and ribose, or metabolized to generate cellular energy either aerobically or anaerobically.glucose 6-phosphate dehydrogenase An enzyme that initiates the oxidative phase of the pentose phosphate pathway by oxidizing glucose 6-phosphate to 6-phosphoglucono-ä-lactone to generate one molecule of NADPH.glucose homeostasis Maintenance of a constant level of glucose in the blood.glucose transporter An integral membrane protein consisting of a single polypeptide chain that has 12 transmembrane segments and facilitates the movement of glucose across the plasma membrane into the cell.glucose-alanine cycle A cycle that allows the use of branched chain amino acids by muscle as a fuel.The nitrogen removed from the branched chain amino acids is transferred to pyruvate to form alanine, which is released into the bloodstream.In the liver, alanine is taken up and converted into pyruvate for the subsequent synthesis of glucose.glutamate dehydrogenase An enzyme that catalyzes the oxidative deamination of glutamate, yielding ammonium ion and α-ketoglutarate.glutamine phosphoribosyl amidotransferase The enzyme catalyzing the committed step in purine synthesis.The pyrophosphate of PRPP is replaced by ammonia, to produce 5-phosphoribosyl-1-amine.glutamine phosphoryl amidotransferase An enzyme that catalyzes the committed step in purine synthesis, which is the displacement of pyrophosphate in 5-phosphoribosyl-1-pyrophosphate by ammonia to yield 5-phosphoribosyl-1-amine with the amine in the β configuration.glutathione(-glutamylcysteinylglycine or GSH)A tripeptide playing a role in combating oxidative stress by maintaining the reduced state of the cell.Glutathione cycles between the reduced(GSH)and oxidized(GSSG)state.glycerol 3-phosphate shuttle A pathway that transfers electrons from cytoplasmic NADH into the mitochondria;dihydroxyacetone phosphate(DHAP)is reduced by NADH to glycerol 3-phosphate, which enters the mitochondria and is oxidized to yield FADH2 and DHAP, which leaves the mitochondria.glyceryl ether phospholipid A phospholipid that contains an ether unit rather than an acyl unit at C-1 and is synthesized starting with dihydroxyacetone phosphate rather than glycerol phosphate.glycobiology The study of the synthesis and structure of carbohydrates and how carbohydrates are attached to and recognized by other molecules such as proteins.glycoforms Forms of a specific protein that differ only in patterns of glycosylation.glycogen A readily mobilized storage form of glucose in which the glucose monomers are linked by α-1,4-glycosidic bonds and with branches(α-1,6-glycosidic bonds)at about every tenth residue.glycogen degradation The cleavage of glycogen by phosphorolysis, catalyzed by glycogen phosphorylase, to yield glucose 1-phosphate, which can be converted into glucose 6-phosphate.15 glycogen phosphorylase An enzyme that catalyzes the phosphorolysis of glycogen to yield glucose 1-phosphate;an allosteric enzyme whose activity is further regulated by reversible covalent modification.glycogen storage diseases Any of a number of heritable diseases characterized by an inability to store or utilize glycogen appropriately.glycogen synthase An allosteric enzyme that can be reversibly covalently regulated and is responsible for the synthesis of glycogen;it transfers glucose from UDP-glucose to the hydroxyl group at a C-4 terminus of glycogen.glycogen synthesis The synthesis of glycogen from UDP-glucose, which is catalyzed by the enzyme glycogen synthase.glycolipids Sugar-containing lipids that are derived from sphingosine;the sugar moiety is attached at the alcohol on sphingosine.glycolysis A sequence of reactions that convert glucose into pyruvate with the concomitant generation of energy.glycomics The study of the glycome, all of the carbohydrates and carbohydrate-associated molecules that cells produce.Like the proteome, the glycome is not static and can change, depending on cellular and environmental conditions.glycoproteins Proteins that have a specific carbohydrate moiety attached.glycosaminoglycan A heteropolysaccharide made of repeating disaccharide units and containing the amino sugar glucosamine or galactosamine.glycosidase A class of enzymes that cleave glycosidic bonds;lysozyme is a glycosidase.glycosidic bond A covalent bond between an aldehyde or ketone function of a monosaccharide and an oxygen, nitrogen, or sulfur atom of another molecule.The most common glycosidic linkages are O-links between the anomeric carbon atom of a sugar and a hydroxyl group of another saccharide.glycosyltransferase Any one of a number of specific enzymes that catalyze the formation of glycosidic bonds.glyoxylate cycle A metabolic pathway that converts two-carbon units into succinate for energy production and biosyntheses;found primarily in bacteria and plants, the cycle bypasses two decarboxylation steps in the citric acid cycle and allows the net formation of glucose and other molecules through oxaloacetate from acetate or acetyl CoA.glyoxysomes Plant organelles in which enzymes of the glyoxylate pathway are present.Golgi complex In the cytoplasm, a stack of membranous sacks that constitute the major sorting center for proteins that reside in cell membranes and the lumen of organelles.gout A disease characterized by inflammation of the joints and kidneys due to the precipitation of abnormally high levels of sodium urate, a breakdown product of purines.green fluorescent protein A protein isolated from the jelly fish Aequorea victoria that fluoresces.Because the protein can be attached to other proteins by genetic engineering techniques, it provides a means of localizing proteins in cells.group-specific reagent A chemical agent that reacts with the side chain of specific amino acid.Group-specific reagents can be used to probe protein function.group-transfer reaction A reaction in which a chemical group is transferred from one molecule to another.guanylate cyclase An enzyme that catalyzes the synthesis of cGMP, a second messenger, from GTP.H

hairpin loop A loop of nucleic acid formed by duplex formation within a single strand.Haworth projection A depiction of a cyclic carbohydrate in which the plane of each ring is perpendicular to the plane of the page and in which ring carbon atoms are not explicitly shown.HDL(high-density lipoprotein)A lipoprotein that collects cholesterol released into the blood from dying cells or from membranes undergoing turnover.heat-shock proteins A ubiquitous group of proteins that are synthesized in response to stress, such as a heat shock, and that bind unfolded polypeptides and assist in their refolding.heavy(H)chain A 50-kd polypeptide that is one of two types of paired chains found in the immunoglobulin G molecule;each heavy chain consists of a variable region and three constant regions, and each chain is linked by a disulfide bond to a light chain.heme The prosthetic group of myoglobin and hemoglobin as well as other proteins;consists of an organic constituent, protoporphyrin, and an iron atom.hemiacetal A compound formed by the reaction of an aldehyde functional group and a hydroxyl group;for example, the C-1 group of the open-chain form of glucose reacts with the C-5 hydroxyl group to form an intermolecular hemiacetal.hemiketal A compound formed by the reaction of a ketone group and a hydroxyl group;for example, the C-2 keto group of the open-chain form of fructose reacts with the C-5 hydroxyl group to form an intermolecular hemiketal.hemoglobin An allosteric protein that is the primary oxygen-carrying protein in vertebrates;it also plays a role in the transport of CO2 and H+.hemoglobin H Hemoglobin, which forms in the absence of the  chain, that consists only  chains.Hemoglobin H binds oxygen with high affinity and displays no cooperativity.hemoglobin S a mutant form of hemoglobin and the cause of sickle cell anemia that aggregates when the oxygen concentration is low, which in turn causes the red blood cells to form sickle shapes that impede blood flow in capillaries.hemophilia A general term for a number of disorders of blood clotting, in which one or another protein in the blood-clotting pathway is defective or missing.heterotropic effects The effects of nonsubstrate molecules on allosteric enzymes.hexokinase A kinase that phosphorylates six-carbon sugars, usually glucose, at the expense of ATP.hexose monophosphate pool

The mixture of fructose 6-phosphate, glucose 1-phosphate and glucose 6-phosphate present in cells.hexoses Monosaccharides that have six carbons.high-density lipoprotein(HDL)A lipoprotein that picks up cholesterol from dying cells and from membranes undergoing turnover, esterifies it, and then transfers the cholesterol esters to the liver and other steroid-synthesizing tissues.high-pressure liquid chromatography A column chromatography technique in which the column materials are very finely divided and, as a consequence, possess more interaction sites and thus greater resolving power.Because the column is made of finer material, pressure must be applied to the column to obtain adequate flow rates.The net result is both high resolution and rapid separation.Hill coefficient The slope of the line generated by a Hill plot.The Hill coefficient is a measure of cooperativity in ligand binding.17 Hill plot A plot of log(Y/1-Y)versus log(pO2), where Y is fractional saturation and pO2 is partial pressure of oxygen, that can be used to determine the degree of cooperativity of oxygen binding.histone acetyltransferase(HAT)An enzyme that catalyzes the attachment of acetyl groups from acetyl CoA to specific lysine residues in the amino-terminal domains of histones.These enzymes play crucial roles in the modification of chromatin structure that enhances transcription.histone deacetylase An enzyme that contributes to transcriptional repression by deacetylation of acetylated lysine residues in histones.histones A highly conserved group of small basic proteins found in eukaryotes in association with DNA to form nucleosomes.holoenzyme An enzyme that consists of the protein component forming the main body of the enzyme(the apoenzyme)and any necessary, usually small, cofactors.homotropic effects The effects of substrate molecules on allosteric enzymes.horizontal gene transfer The passing of pieces of DNA(plasmids)between species that provide a selective advantage in particular environments.human immunodeficiency virus(HIV)The cause of acquired immune deficiency syndrome(AIDS).HIV destroys helper T cells by increasing the permeability of the T cell membrane.Loss of the helper T cells severely cripples the immune system, rendering the victim susceptible to many types of infection.hydratase An enzyme that adds the elements of water to a carbon-carbon double bond.hydrogen bond A bond formed when two relatively electronegative atoms, such as oxygen or nitrogen, unequally share a hydrogen atom that is covalently bonded to one of the electronegative atoms.hydrolase A class of enzymes that cleaves bonds by the addition of water(transfer of functional groups to water).hydrolytic reactions Reactions in which bonds are cleaved by the addition of water.hydrophobic effect The tendency of hydrophobic molecules to associate with one another in water.The association is powered by the resulting increase in the entropy of water.hydrophobic interactions Refers to the tendency of nonpolar molecules in water to interact with one another;the interactions are driven by an increase in the entropy of water when the water molecules in contact with the nonpolar molecules are released into bulk water.3-hydroxy-3-methylglutaryl CoA reductase(HMG-CoA reductase)A highly regulated enzyme that catalyzes the committed step in cholesterol synthesis-the formation of mevalonate from 3-hydroxy-3-methylglutaryl CoA.hydroxyproline A derivative of proline that has a hydroxyl group in place of one of the hydrogen atoms on the pyrrolidine rings.Hydroxyproline is a key constituent of collagen.hyperammonemia A condition characterized by high levels of ammonia in the blood due to deficiencies in the urea cycle, which can result in brain damage and death.hypoxanthine A purine base that reacts with 5-phosphoribosyl-1-pyrophosphate(PRPP)to form inosinate;the reaction is part of the salvage pathway for purine nucleotides.I

IDLs(intermediate-density lipoproteins)Lipoprotein particles that remain after much of the triacylglycerides from VLDL are hydrolyzed and absorbed by other tissues;can be absorbed by the liver or converted into LDL.immunoglobulin A(IgA)The major class of antibodies in external secretions, such as saliva, tears, bronchial mucus and intestinal mucus.immunoglobulin D(IgD)An antibody of unknown function.immunoglobulin fold A common structural motif for immunoglobulins, in which two broad sheets of antiparallel β strands enclose hydrophobic side chains, and complementarity-determining regions of variable domains pair to form an antigen-binding site.immunoglobulin G(IgG)The major antibody in serum;IgG posses two antigen-binding sites.immunoglobulin M(IgM)The first class of antibodies to appear in the serum after exposure to an antigen;IgM posseses ten antigen-binding sites.induced fit The modification of the shape of an active site in an enzyme after the substrate is bound.induced pluripotent stem(iPS)cell Pluripotent stem cells, which have the ability to differentiate into many different cell types on appropriate treatment, generated by introducing genes encoding four transcription factors into skin cells called fibroblasts.inducer A small molecule that binds to a repressor and alters its interaction with an operator.inhibition constant A measure of the strength of binding of an inhibitor to an enzyme.Ki = [E] [I]/[EI] where [S] is the concentration of free enzyme, [I] is the concentration of free inhibitor, and [EI] is the concentration of the enzyme-inhibitor complex.inhibitor 1 A protein that, when phosphorylated, inhibits the activity of protein phosphatase 1 and thereby sustains glycogen breakdown and inhibits glycogen synthesis.initiation complex A complex of an RNA polymerase, promoter elements, and specific transcription factors that permits the initiation of RNA synthesis.initiation factor One of a set of proteins that assist in the association of the ribosome, mRNA, and initiator tRNA to initiate the process of protein synthesis.initiation The first of the three stages common to all biological polymerization reactions;this stage establishes conditions for the beginning of the polymerization process.in-line displacement A hydrolysis reaction, characteristic of restriction enzymes, in which the incoming nucleophile attacks the phosphorus atom.The transition state has a trigonal bipyramidal geometry centered at the phosphorus atom, with the incoming nucleophile at one apex of the two pyramids and the group that is displaced(the leaving group)at the other apex, in line with the incoming nucleophile.innate immune system An evolutionarily ancient defense system that responds rapidly to features present in many pathogens.The innate immune systems includes the epithelial lining that surrounds host cell, phagocytes, and a family of receptors that can recognize specific features present in most pathogens.inosinate A purine nucleotide formed by the reaction of hypoxanthine with 5-phosphoribosyl-1-pyrophosphate(PRPP);a precursor to both AMP and GMP.inositol 1,4,5-trisphosphate A second messenger of the phosphoinositide cascade that causes an increase in intracellular calcium levels.insertion A type of mutation in which one or more base pairs are erroneously inserted into DNA.insertion sequence A simple DNA transposon, composed of a kilobase sequence that specifies a transposase and is bounded on either end by inverted terminal repeats;an insertion sequence can insert itself into any site on a bacterial chromosome.insertional inactivation Gene inactivation that occurs when an unrelated DNA fragment is inserted at a restriction site;inactivation of a gene for antibiotic resistance in a plasmid can be used to detect those plasmids in which a DNA fragment has been successfully inserted.insig An integral membrane protein of the endoplasmic reticulum that binds SCAP and thereby SREBP when cholesterol levels are adequate.This binding prevents the activation of SREP and the synthesis of cholesterol.insulin A polypeptide hormone secreted by the á cells of the pancreas, that stimulates fuel storage and protein synthesis.insulin receptor A receptor tyrosine kinase that mediates the action of insulin.insulin resistance A condition marked by a normal or elevated levels of blood insulin, but cells are nonetheless unresponsive to the hormone.insulin-receptor substate(IRS)Adaptor proteins that bind to phosphorylated insulin receptor and, in turn, are phosphorylated by the receptor.Other proteins bind to the phosphorylated IRS to propagate the insulin signal.integral membrane proteins Proteins found in membranes that interact extensively with the hydrocarbon chains of the membrane lipids and usually span the membrane.intercalating agents Flat, aromatic compounds that can insert between adjacent base pairs in a DNA double helix;these agents, such as ethidium bromide, can cause insertions and deletions.intermediate filaments Filaments ranging from approximately 7 to10 nm in diameter that can be components of the cell cytoskeleton in epithelial cells;keratins are intermediate filaments.intrinsic clotting pathway The-blood clotting cascade of enzyme activities that is initiated by the activation of factor XII through contact of activating proteins(kininogen and kallikrein)with abnormal cell surfaces produced by injury;at least six proteins are activated in the pathway to thrombin formation and the continuing sequence that leads to a blood clot.intrinsically unstructured protein(IUP)Proteins that, completely or in part, do not have a discrete three-dimensional structure under physiological conditions, but assume a defined structure upon interaction with other proteins.introns Regions of the primary transcript that are removed in the mature mRNA.Also called intervening sequences.inversion A nucleotide sequence whose normal order is reversed in a gene or in a chromosome.inverted terminal repeats Sequences of 20 or so base pairs at opposite ends of a bacterial insertion sequence.ion channels Passive transport systems for ions capable of very high transport rates;ion channels often display a high degree of specificity for the transported ion.ion-exchange chromatography A protein purification technique that relies on the charge of proteins.Proteins are applied to an inert matrix to which is attached a charged moiety(e.g., a carboxylate group).Proteins will bind to the matrix with an affinity proportional to their content of the counterion(i.e., positive charges in regard to the carboxylate matrix).iron-sulfur proteins Proteins that contain clusters of iron and sulfur that play a role in electron transfer reactions;iron cycles between the Fe2+ and Fe3+ state.Also called nonheme iron proteins.irreversible inhibitor An inhibitor that binds very tightly to its target enzyme, either covalently or noncovalently;such an inhibitor dissociates very slowly from the enzyme.isocitrate dehydrogenase An enzyme that catalyzes the oxidative decarboxylation of isocitrate to form α-ketoglutarate;plays a role in controlling the rate of the citric acid cycle.isocitrate lyase An enzyme of the glyoxylate cycle, isocitrate lyase cleaves isocitrate into succinate and glyoxylate.isoelectric focusing A technique for separating proteins.A mixture of proteins is undergoes electrophoresis in a pH gradient;each protein will migrate in the electrical field until it reaches its isoelectric point.isoelectric point(pI)The pH of a protein at which its net charge is equal to zero.isomerase An enzyme that catalyzes the interconversion of isomeric forms of a compound.isopentenyl pyrophosphate Activated isoprene;the basic building block of cholesterol.3-isopentyl pyrophosphate A precursor to cholesterol as well as a large variety of other biomolecules such as vitamin K, coenzyme Q, and the carotenoids.Isopentyl pyrophosphate is derived from mevalonate.isopropylthiogalactoside(IPTG)An inducer of the lac operon;ITPG binds to the lac repressor and reduces the repressor's affinity for the operator DNA, which permits transcription to take place.isozymes Enzymes in an organism that catalyze the same reaction but differ in structure;these differences may range from one to several amino acid residues.Also called isoenzymes.J

joule The amount of energy needed to apply a 1-newton force over a distance of 1 meter;a kilojoule(kJ)is equal to 1000 J, or to 0.239 kcal.K

ketogenic amino acids Amino acids whose carbon skeletons, entirely or in part, are degraded into acetyl CoA or acetoacetyl CoA;only leucine and lysine are solely ketogenic.ketone body Refers to acetoacetate, β-hydroxybutyrate, and acetone, produced when acetyl CoA is diverted from the citric acid cycle to the formation of acetoacetyl CoA in the liver;subsequent reactions generate the three compounds, known as ketone bodies.ketose A monosaccharide that has a ketone group as its most oxidized carbon.α-ketoglutarate dehydrogenase A citric acid cycle enzyme that catalyzes the oxidative decarboxylation of α-ketoglutarate to yield succinyl CoA;this enzyme, which helps to regulate the rate of the citric acid cycle, is structurally and mechanistically similar to the pyruvate dehydrogenase complex.kilobase A unit of length equal to 1000 base pairs of a double-stranded nucleic acid molecule or to 1000 bases of a single-stranded molecule.kilocalorie(kcal)A unit of energy equal to 1000 calories, or 4.184 joules.kinase An enzyme that catalyzes the attachment of a phosphoryl group to a substrate by using ATP as a phosphoryl donor.Krebs cycle See citric acid cycle.L

lac operon The operon that encodes the genes required for lactose metabolism.lac repressor The regulator protein that binds to the operator site of the lac operon and thereby inhibits expression of the structural genes of the operon;inhibition is relieved when the repressor protein binds allolactose, an inducer of the lac operon.lactic acid fermentation The anaerobic metabolism of glucose to yield lactic acid with the concomitant production of ATP.21 lectins Plant proteins with a high affinity for specific sugar residues;as such, they are important probes of carbohydrate-containing molecules.leptin A polypeptide hormone, secreted by the adipocytes in direct proportion to fat mass, that generates satiation signals.Lesch–Nyhan syndrome A syndrome, associated with a lack of the purine salvage pathway enzyme hypoxanthine-guanine phosphoribosyl transferase, that is characterized by compulsive self-destructive behavior, mental deficiency, spasticity and aggressiveness toward others.ligand A small molecule that binds to a protein, inducing a specific structural change.For instance, a steroid is a ligand for a steroid-hormone receptor.ligand-gated channel A transmembrane channel that is opened by the binding of a one or more molecules to a ligand-binding domain of the channel protein.light(L)chain A 25-kd polypeptide that is one of two types of chains found in immunoglobulin G.Each L chain consists of a variable region and a constant region, and each chain is linked by a disulfide bond to a heavy chain.lipid bilayer A bimolecular sheet formed by amphipathic molecules in which the hydrophobic moieties are on the inside of the sheet and the hydrophilic ones are on the aqueous outside.lipid raft Membrane structures that result when cholesterol forms specific complexes with sphingolipids, certain glycolipids, and specific GPI-anchored proteins.These complexes concentrate within small(10–200 nm)and highly dynamic regions within membranes.lipoic acid(6, 8-dithiooctanoic acid)An acyl group carrier that functions as a cofactor in dehydrogenase enzymes;linked covalently to specific lysine residues in enzyme proteins, it can exist as the reduced open-chain form or the closed-ring disulfide form, undergoing interconversion in a catalytic cycle.lipoprotein particles Particles, consisting of a core of hydrophobic lipids surrounded by a shell of polar lipids and specific proteins, that play a role in the transport of cholesterol and triacylglycerols.lovastatin A competitive inhibitor of HMG-CoA reductase, the key regulatory enzyme in cholesterol biosynthesis;used therapeutically to lower cholesterol levels.Also called mevinolin.low-density lipoprotein(LDL)The major carrier of cholesterol in the blood;consists of a core of esterified cholesterol molecules surrounded by a shell of phospholipids, unesterified cholesterol, and apoprotein B-100;primary source of cholesterol for cells other than the liver or intestine.lyase A class of enzymes that catalyze the addition or removal of groups to form double bonds.M

major groove A 12-Å-wide, 8.5-Å-deep groove in B-DNA resulting from the fact that the glycosidic bonds of a base pair are not diametrically opposite each other.malaria A disease carried by a mosquito parasite, Plasmodium falciparum, that lives within red blood cells at one stage in its life cycle.The presence of one allele for hemoglobin S confers resistance to malaria.malate synthase An enzyme of the glyoxylate cycle that catalyzes the formation of oxaloacetate from glyoxylate and acetyl CoA.malate–aspartate shuttle A means to transport electrons from cytoplasmic NADH into the mitochondria to reform NADH.The shuttle, which is common in heart and liver, consists of two membrane carriers and four enzymes.malate-aspartate shuttle A reversible shuttle, found in the liver and heart, used to transport electrons from cytoplasmic NADH to mitochondrial NAD+.malonyl CoA The activated form of acetyl CoA required for fatty acid synthesis.Malonyl CoA also inhibits fatty acid degradation.matrix-assisted laser desorption/ionization(MALDI)A technique for determining a proteins mass.The protein is evaporated to dryness in the presence of a volatile, aromatic compound that can absorb light at specific wavelengths.A laser pulse excites and vaporizes the matrix, converting some of the protein into the gas phase.Subsequent collisions enable the intermolecular transfer of charge, ionizing the protein.The newly formed ions then enter the mass analyzer, where they are distinguished on the basis of their mass-to-charge ratios.maximal velocity The highest rate of an enzyme-catalyzed reaction, under conditions of constant enzyme concentration and saturating amounts of substrate.melting temperature The temperature at which secondary or higher structures of a biological molecule are lost;for a nucleic acid, the melting temperature is defined as the temperature at which half the helical structure is lost.membrane asymmetry Refers to the fact that the two phases of biologically important membranes differ from each other.membranes Sheetlike structures composed of lipids and proteins, usually only a few molecules thick, that form closed boundaries between different compartments;membranes separate aqueous environments

messenger RNA(mRNA)Template for protein synthesis;the base sequence of mRNA is complementary to that of a gene in DNA.metabolism A highly integrated network of chemical pathways that enables a cell to extract energy from the environment and use this energy for biosynthetic purposes.metabolite Low-molecular-weight molecules such as glucose and glycerol that are chemically transformed in biological processes.metal ion catalysis Catalysis in which a metal acts as an electrophilic catalyst by stabilizing a negative charge on a reaction intermediate, generates a nucleophile by increasing the acidity of nearby molecules, or increases the binding energy of the enzyme-substrate interaction by binding to substrates.methylases In general, an enzyme that attaches a methyl group to a molecule.Methylases modify the recognition sites for restriction enzymes in bacterial DNA in order to prevent digestion by the bacteria’s own restriction enzymes.mevalonate A precursor for the synthesis of cholesterol;its formation by HMG-CoA reductase constitutes the committed step in cholesterol biosynthesis.micelle A globular structure formed by amphipathic molecules in which the hydrophilic part is exposed to water and the hydrophobic part is sequestered inside, away from the water.Michaelis constant The concentration of substrate at which half the active sites of an enzyme are filled;a ratio of rate constants for the reaction model.E + S ES E + P, k1 k2,k-1;The constant is defined as KM = k-1+ k2/k1.Under conditions where k-1 is much greater than k2, KM is equal to the dissociation constant of the enzyme-substrate complex and is a measure of the affinity of the enzyme for the substrate.Michaelis-Menten equation An equation that expresses the velocity(V)of an enzyme-catalyzed reaction in terms of maximum velocity(V/max), substrate concentration(S), and the Michaelis-Menten constant(KM).The equation accounts for the hyperbolic kinetics observed when V is plotted as a function of S;the equation is V = Vmax [S]/([S] + KM).microRNA(miRNA)RNA molecule 22-nucleotides in length that possesses the regulatory activity when bound to members of a class of proteins called the Argonaute family.microsomes Closed vesicles formed by self-annealing fragments of the endoplasmic reticulum subsequent to following cell disruption.minor groove A 6-Å-wide, 7.5-Å-deep groove in B-DNA that arises because the glycosidic bonds of a base pair are not diametrically opposite one another.mitochondrion An oval-shaped organelle, about 2 Mm in length and 0.5 Mm in diameter, that is the site of oxidative phosphorylation, the enzymes of the citric acid cycle, and the enzymes of fatty acid oxidation.monoclonal antibody An antibody derived from a clone-a large number of cells that are all descended from the same cell and have identical properties.Normally, antigens with a common specificity are heterogeneous because they are produced by a heterogeneous group of cells.Fusion of a single antigen-producing cell with an immortal myeloma cell facilitates the production of large amounts of homogeneous antibody protein, these antibodies are valuable analytical and preparative reagents.monosaccharides Single aldehydes or ketones that have two or more hydroxyl groups;the simplest carbohydrates.multienzyme complex A polypeptide chain that contains domains for two or more enzymatic activities.multifunctional enzymes Functionally related enzymes that are covalently linked in some fashion.mutarotation For carbohydrates, the interconversion of α and β anomers through the open-chain form;usually measured through changes in optical rotation.myoglobin A vertebrate oxygen-storage protein found in muscle;structurally similar to an individual hemoglobin subunit.N

N-acetylglutamate An allosteric activator of mammalian carbamoyl phosphate synthetase, which catalyses the synthesis of urea.NAD+ and NADH(nicotinamide adenine dinucleotide)An important electron carrier in the oxidation of fuel molecules;electrons are carried on the nicotinamide moiety of the coenzyme.NAD-binding domain A structural motif of NAD+-linked dehydrogenases that forms a binding site for NAD+ and consists of four helices and six parallel β strands.NADH-Q oxidoreductase A large component of the respiratory chain that transfers electrons from NADH to ubiquinone and in the process pumps protons across the inner mitochondrial membrane to generate the proton-motive force.Also called NADH dehydrogenase or Complex I.NADP+ and NADPH(nicotinamide adenine dinucleotide phosphate)The electron donor for reductive biosynthesis;differs from NAD+ and NADH in that a phosphate is attached to the adenine ribose at position 3.negative nitrogen balance A physiological state in which more protein is degraded than is synthesized, and so more nitrogen is excreted than is ingested.nicotinate A vitamin that is a key component of the electron-transfer coenzymes NAD+, NADH, NADP+, and NADPH.Also called niacine.nitric oxide(NO)A free-radical gas, synthesized from arginine, that is an important messenger in many vertebrate signal transduction processes.nitrogen fixation The conversion of diatomic nitrogen into ammonia;the first step in the flow of nitrogen into amino acids, nucleotides, and other nitrogen-containing compounds in organisms.noncompetitive inhibition The reduction in the rate of enzyme activity observed when an enzyme can bind its substrate and its inhibitor simultaneously.Noncompetitive inhibitors decrease the turnover number for an enzyme but do not diminish the proportion of enzyme molecules bound to the substrate;their effects are not overcome by increasing substrate concentration.nonessential amino acids Amino acids that can be synthesized by an organism and are thus not a dietary requirement.nonreducing sugar A sugar that is not readily converted into a form with a free aldehyde group capable of reducing another compound.Such a conversion is prevented because the sugar forms a glycosidic bond with another compound.N-terminal rule The dependency of the half-life of a cytosolic protein on the nature of its N-terminal amino acid.nuclear magnetic resonance(NMR)spectroscopy An analytical technique that exploits intrinsically magnetic properties of certain atomic nuclei in proteins to determine the structure of a protein in solution.nucleoside A purine or pyrimidine base linked to a sugar.nucleotide A nitrogenous purine or pyrimidine base linked to a sugar, which is in turn linked to one or more phosphate groups.nucleotide kinases Enzymes that transfer the phosphoryl group of one nucleotide to another nucleotide, as in the reaction of ATP with UMP to form UDP and ADP.O

Okazaki fragments Small fragments of DNA(approximately 1000 nucleotides)that are formed on the lagging strand at the replication fork of DNA synthesis and later joined;enable 5'.3' polymerization at the nucleotide level while overall growth is in the 3'.5'direction.oligomycin An antibiotic that blocks ATP synthesis(and consequently the respiratory chain)by interfering with proton flow through the ATP synthase complex.oligosaccharides Carbohydrates composed of 2 to 12 monosaccharide units.oncogene A gene whose expression contributes to the development of cancer.one-carbon metabolism Biochemical reactions in which tetrahydrofolate derivatives serve as donors of a variety of one-carbon units, ranging from the oxidation level of a methyl group to a formyl group;also includes reactions involving the fully oxidized carbon unit, carbon dioxide, and its carrier, biotin.operator A DNA segment that is adjacent to a group of structural genes and is the target sequence for a repressor protein;a unit of gene regulation and expression that includes structural genes and regulatory elements recognized by one or more regulatory gene products.operon model A model of prokaryotic gene regulation that consists of an operator sequence and its associated structural genes.β-oxidation Oxidation of the C-3 carbon atom that is β to a functional group;in the degradation of a fatty acyl CoA molecule, the sequence of oxidation, hydration, and oxidation reactions that converts a methylene group at C-3 into a β-keto group.oxidation-reduction reaction A reaction that transfers electrons.25 oxidative phosphorylation The process in which ATP is formed as a result of the transfer of electrons from NADH or FADH2 to O2 by a series of electron carriers.oxidoreductase A class of enzymes that catalyze oxidation-reduction reaction.oxygen-binding curve A plot of the fractional saturation of oxygen binding proteins versus the concentration of oxygen.oxygen-dissociation curve A plot of the oxygen-binding capacity of a protein versus the partial pressure of oxygen.P

pantothenate A vitamin that is a key component of coenzyme A.partial pressure The fraction of the total pressure of a mixture of gases that is due to one component of the mixture.passive transport Transport of an ion or a molecule down a concentration gradient, where.G for the transported species is negative.Also called facilitated diffusion.Pasteur effect The inhibition of glycolysis by respiration, discovered by Louis Pasteur;the rate of glycolysis is lower in the presence of oxygen than under anaerobic conditions, a phenomenon largely due to the inhibition of phosphofructokinase by ATP and citrate.pentose phosphate pathway A metabolic pathway that generates NADPH and five-carbon sugars such as ribose 5-phosphate from glucose 6-phosphate;it includes oxidative reactions that produce NADPH and ribose 5-phosphates as well as nonoxidative reactions that together convert five-carbon sugar phosphates into gluconeogenic precursors of glucose 6-phosphate.Also referred to as the hexose monophosphate shunt or the phosphogluconate pathway.pentoses Monosaccharides that have five carbon atoms.peptide bond A covalent linkage formed between the α-carboxyl group of one amino acid and the α-amino group of another.Also known as an amide bond.peptide Two or more amino acids joined by peptide bonds.peptidoglycan A macromolecule that consists of linear polysaccharides cross-linked by short peptides;often found in bacterial cell walls, peptidoglycans confer mechanical support and protect bacterial cells from disruption by osmotic pressure.peripheral membrane protein A protein associated with the surface of a membrane by electrostatic and hydrogen-bond interactions.peroxidases Heme enzymes catalyzing the reduction of an alkyl peroxide to produce an alcohol and water.pH The concentration of hydrogen ions in solution.Specifically, the pH of a solution is defined +as pH =-log[H].phosphatase An enzyme that catalyzes the removal of a phosphoryl group from a substrate by hydrolysis.phosphatidate(diacylglycerol 3-phosphate)A precursor to triacylglycerols as well as many phospholipids.phosphoglyceride Phospholipids constructed on a glycerol backbone.phospholipase C The enzyme that catalyzes the cleavage of phosphatidylinositol 4,5-bisphosphate into the two second messengers, inositol 1,4,5-trisphosphate(IP3)and diacylglycerol(DAG), thereby activating the phosphoinositide cascade.26 phospholipases A class of enzymes of varying specificity that catalyze the degradation of phospholipids;can function as digestive enzymes as well as components of signal-transduction pathways.phospholipids Important constituents of membranes and composed of three components: a backbone(usually glycerol or sphingosine), two fatty acid chains, and a phosphorylated alcohol.5-phosphoribosyl-1-pyrophosphate(PRPP)An activated form of ribose that accepts bases in nucleotide synthesis.phosphorolysis The cleavage of a bond by orthophosphate, as in the degradation of glycogen to glucose 1-phosphate.Ping-pong reactions See double-displacement reaction.pKa A measure of the susceptibility of a proton on an acid to removal by reaction with a base.pKa=-(log Ka), where Ka is the proton dissociation constant of the acid.plasmalogens Phospholipids containing an α,β-unsaturated ether at the C-1 position of glycerol;abundant in phospholipids of the nervous system.plasmids Circular duplex DNA molecules that replicate autonomously and act as accessory chromosomes in bacteria;they carry useful genes but are disposable under certain conditions.poly(A)tail A long(as many as 250 nucleotides)polyadenylate segment added posttranscriptionally to the 3' end of most eukaryotic mRNA.polyclonal antibodies Antibodies that are the products of many different populations of antibodyproducing cells.polymerase An enzyme that catalyzes the step-by-step addition of ribo-or deoxyribonucleotide units to a polynucleotide chain.polymerase chain reaction(PCR)A method for amplifying DNA sequences by using DNA polymerase;a series of three-step cycles is employed, in which parental DNA strands are separated by heating, primers to flanking regions of the target sequence are annealed to the separated strands, and the primers are then extended by DNA synthesis.polypeptide A series of amino acids, each connected to the next in the series by a peptide bond.polysaccharides Carbohydrates composed of large numbers of linear or branched monosaccharide units;homopolysaccharides are composed of large numbers of one type of sugar, whereas heteropolysaccharides contain more than one type.pre-mRNA The unspliced, immediate product of RNA polymerase II in eukaryotes.Pribnow box A promoter component of prokaryotic genes that has the consensus sequence 5'-TATAAA-3' located 10 base pairs downstream from the transcription start site.primary active transport A process in which the free energy of ATP hydrolysis is used to drive the movement of ions against their concentration gradients.primary messenger The information embodied in the interaction of ligand with its receptor molecule.primary structure Usually refers to the linear sequence of amino acids in a protein;more generally, the linear sequence of units that form a polymer.primase A specialized RNA polymerase that synthesizes the RNA primers for DNA synthesis.primer In the elongation of polymers, the initial segment of the polymer that is to be extended;elongation depends on the primer.primosome A complex of proteins that facilitate the unwinding of DNA and the synthesis of RNA primers, thus initiating DNA synthesis.proenzyme A zymogen, or a catalytically inactive precursor of an enzyme;a proenzyme can be converted into the active form by the hydrolysis of one or a few peptide bonds.progestagen A class of steroid hormone, exemplified by progesterone, that prepares the uterus for implantation of the ovum;synthesized by the corpus luteum of the ovary.programmed cell death Refers to a cascade of proteolytic enzymes that result in controlled cell death in response to significant cell damage or specific development programs.Also called apoptosis.prokaryote Unicellular organisms, such as bacteria, which lack a nucleus.promoter sites A specific sequence of DNA, usually just upstream of a gene, that specifies the site and extent of transcription of the associated gene.propeller twisting The twisting of base pairs in crystals of DNA from the coplanar conformation;enhances the stacking of bases within a strand.prostaglandins A class of short-lived signal molecules that are 20-carbon fatty acids containing a fivemembered ring.prosthetic group A tightly bound cofactor required for a protein’s activity.protease inhibitor A drug or protein that specifically inhibits a particular proteolytic enzyme.Chemical protease inhibitors are clinically important drugs.proteases Enzymes that degrade proteins by cleaving peptide bonds.proteasomes Large protein complexes that carry out routine degradation of ubiquitinated cellular proteins as well as of those from pathogens.protein A biological macromolecule composed of a linear array of amino acids joined by peptide bonds;roles of proteins in biological processes include catalysis, transport and storage, motion, mechanical support, immune protection, the generation and transmission of nerve impulses, and the control of growth and differentiation.Protein Data Bank(PDB)A Web storage site for the coordinates of protein structures that have been solved by x-ray crystallography and NMR analysis.With the use of the coordinates, the structures can be accessed for visualization and analysis.protein disulfide isomerase An enzyme that catalyzes the formation of correct disulfide pairings in nascent proteins;preferentially reacting with peptides that contain cysteine residues but otherwise undiscriminating, the enzyme speeds up the disulfide shuffling required for a protein to find the most thermodynamically stable disulfide pairings among those that can be formed.protein kinase A(PKA)A protein kinase that consists of two catalytic subunits and two regulatory subunits that inhibit the catalytic subunits;on binding of cAMP, the regulatory subunits dissociate from the catalytic subunits, which then become active.protein kinase C(PKC)A protein kinase that is activated by the binding of diacylglycerol.protein kinases A class of enzymes that transfer a phosphoryl group from ATP to proteins;protein kinases are frequently found in regulatory pathways.protein phosphatases Enzymes that hydrolyze phosphorylated serine and threonine residues in other proteins;protein phosphatase 1 reverses the regulatory effects of kinases on glycogen metabolism.proteoglycans Proteins containing one or more covalently linked glycosaminoglycan chains;cartilage proteoglycan contains keratan sulfate and chondroitin chains linked to a polypeptide backbone.proteome The functional representation of the genome that includes the types, functions, and interactions of proteins that are present in a cell;the proteome is not a fixed characteristic of a cell but will vary, depending on such factors as developmental stage or hormonal status.proton gradient The unequal distribution of protons across a proton-impermeable membrane;such gradients can be used to power various biochemical processes, such as the synthesis of ATP.proton-motive force The energy inherent in the proton gradient established during the functioning of the respiratory chain;consists of a membrane potential as well as a chemical gradient.proto-oncogene A signal transduction protein that usually regulates cell growth in some fashion;when proto-oncogenes mutated, they become oncogenes and contribute to the development of cancer.protoporphyrin An organic constituent of the heme prosthetic group;consists of four pyrrole rings joined by methylene bridges and contains various side chains.proximal histidine The histidine that binds the fifth coordination site of the heme in myoglobin and hemoglobin.pseudogenes Sequences of DNA that resemble actual genes but do not encode functional products.pseudosubstrate An amino acid sequence that resembles the actual substrate for an enzyme except that a crucial amino acid has been changed, converting the sequence into an inhibitor;the regulated binding of pseudosubstrates is sometimes used to control enzyme activity.pump A protein passage in a membrane that can transport a molecule from one compartment to another against a concentration gradient;pumps undergo a cycle of conformational changes that alter the affinity of the binding site for the transported molecule, and the eversion of the molecule during the cycle is driven by expenditure of free energy.Also called active transporters.purine A nitrogenous base that includes a pyrimidine ring fused with a five-membered imidazole ring;the purine derivatives adenine and guanine are found in nucleotides and nucleic acids.pyranose A six-membered heterocyclic ring formed when a monosaccharide cyclizes to form a hemiacetal or a hemiketal;the six-membered, oxygen-containing ring is similar to that of pyran.pyridine nucleotides Nucleotides, such as NAD+, NADH, NADP+, and NADPH, that are employed in redox reactions;the functional group is nicotinamide, a derivative of pyridine.pyridoxal phosphate(PLP)A prosthetic group derived from vitamin B6(pyridoxine)that plays a key role in transamination reactions.pyridoxamine phosphate(PMP)An aminated form of pyridoxal phosphate that is an intermediate in transamination reactions.pyrimidine A nitrogenous base that is a six-membered heterocyclic ring containing two nitrogen atoms and four carbon atoms;the pyrimidine derivatives cytosine, uracil, and thymine are found in nucleotides and nucleic acids.pyruvate A prominent intermediate in metabolism;a precursor for alanine and glucose and can be converted into lactate in anaerobic glycolysis;can also be oxidized to acetyl CoA, which can be further oxidized to yield energy aerobically, converted into fats, or used to synthesize cholesterol and other steroids.pyruvate carboxylase A biotin-dependent enzyme that catalyzes the formation of oxaloacetate from pyruvate and CO2 at the expense of ATP;important in gluconeogenesis as well as in the replenishment of the citric acid cycle.pyruvate dehydrogenase complex A large, complex mitochondrial enzyme that catalyzes the oxidative decarboxylation of pyruvate to form acetyl CoA;this irreversible reaction is the link between glycolysis and the citric acid cycle.pyruvate dehydrogenase kinase(PDK)A component of the pyruvate dehydrogenase complex in eukaryotes that phosphorylates and inhibits the pyruvate dehydrogenase component of the complex.pyruvate dehydrogenase phosphatase(PDP)A component of the pyruvate dehydrogenase complex in eukaryotes that dephosphorylates and activates the pyruvate dehydrogenase component of the complex.pyruvate kinase A key regulatory enzyme in glycolysis that catalyzes the formation of ATP and pyruvate from phosphoenolpyruvate and ADP.Q

Q cycle A set of reactions in which coenzyme Q cycles between the fully reduced state and the fully oxidized state through one-electron transfer reactions in which one of the electrons is temporarily stored in cytochrome b;provides a means of passing the two electrons of coenzyme Q to the single-electron carrier cytochrome c, one electron at a time.Q-cytochrome c oxidoreductase A component of the respiratory chain, this oxidoreductase carries electrons from coenzyme Q to cytochrome c and, in the process, pumps protons out of the mitochondrial matrix to generate the proton-motive force.Also called cytochrome reductase or Complex III.quantitative PCR(qPCR)A polymerase chain reaction-based technique for determining the amount of individual mRNA molecules present in a population of RNA molecules.quaternary structure In proteins containing more than one polypeptide chain, the spatial arrangements of those chains(subunits)and the nature of contacts among them.R

R state The more active state of allosteric proteins, which is in equilibrium with the less active T-state.random-coil conformation The disordered, unfolded structure of a denatured macromolecule;many proteins that are not cross-linked lose their native three-dimensional structure as well as their biological function in the presence of unfolding agents such as urea.Ras A member of a class of signal transduction proteins called small G proteins.These proteins bind GDP in their inactive forms and GTP in their active forms.recombinant DNA technology An array of techniques used to analyze and manipulate DNA;these methods include the specific modification of genes as well as the construction of new ones, gene cloning and amplification, and the expression of new and modified genes to yield protein products.recombination The formation of new arrangements of genes or gene sequences by movement of DNA.reducing sugars Sugars that convert into a form with a free aldehyde group that is readily oxidized and can thus reduce another compound.reductase An enzyme that catalyzes the reduction of a functional group, often using NADPH as an electron donor;a type of oxidoreductase.regulatory proteins Proteins that bind to enzymes and regulate their catalytic activity.relaxed DNA A circular DNA molecule that has no superhelical turns.respiration An ATP-generating process in which an inorganic compound, such as O2, serves as the ultimate electron acceptor;the electron donor can be either an organic compound or an inorganic one.30 respiratory chain The path that electrons travel in going from NADH or FADH2 to O2;consists of three complexes that pump protons as a result of the electron transport and two mobile electron carriers.Also called the electron transport chain.respiratory control Tight coupling or coordination of the oxidation of reduced cofactors(NADH and FADH2)in the electron-transport chain and the phosphorylation of ADP to yield ATP in the mitochondrion;such control ensures that the rate of the citric acid cycle, where reduced cofactors are generated, corresponds to the demand for ATP.restriction enzymes Endonuclease enzymes that recognize specific base sequences in double-stranded DNA and cleave both strands of the duplex at specific places.restriction-fragment-length polymorphism(RFLP)The genetic diversity within a population indicated by mutations within specific sites in DNA;such mutations alter the position of restriction fragments in electrophoretic gel analysis.retinal The prosthetic group of rhodopsin that, upon absorbing light, undergoes an isomerization from 11-cis-retinal to all-trans-retinal, initiating the visual signal transduction pathway.retrovirus A virus that contains an RNA genome but that replicates through the intermediacy of double-stranded DNA that is integrated into the host-cell genome.reverse cholesterol transport The retrieval of cholesterol from peripheral tissues by HDL for return to the liver for excretion as bile or in the feces.reverse transcriptase An enzyme that synthesizes DNA by using an RNA template.riboflavin A vitamin component of the electron-transfer coenzymes FAD, FADH2, FMN, and FMNH2.Also called vitamin B2.ribonucleotide A nucleotide that contains a purine or pyrimidine base covalently linked to a ribose, which is in turn linked to one or more phosphate groups.ribonucleotide reductase An enzyme that catalyzes the reduction of all four ribonucleotides to deoxyribonucleotides.ribose A five-carbon monosaccharide(C5H10O5)that constitutes the carbohydrate moiety of ATP, other ribonucleosides and ribonucleotides, and cofactors such as NAD and coenzyme A.ribosomal RNA The RNA component of a ribosome, the site of protein synthesis.ribosome A large ribonucleoprotein assembly that catalyzes the formation of peptide bonds;a molecular machine that coordinates protein synthesis.ribozymes RNA molecules that display enzymatic activity.rickets A disease caused by the insufficient formation of vitamin D, resulting in the inadequate calcification of cartilage and bone.rifamycin An antibiotic isolated from Streptomyces that inhibits the initiation of RNA synthesis by blocking the formation of the first phosphodiester bond.RNA enzymes RNA molecules that act as enzymes.Also called ribozymes.RNA interference The suppression of the transcription of a gene following the introduction into the cell of double stranded RNA molecule that contained sequences present in the suppressed gene.RNA polymerases A class of enzymes that synthesize RNA molecules complementary to a DNA template.RNA primers Small pieces of RNA that base-pair with the template strand of DNA and serve as primers for primer-dependent DNA synthesis;the RNA is later removed and replaced by DNA.RNA processing Any alteration of a precursor RNA molecule, such as splicing or polyadenylation, that yields a mature RNA molecule.31 RNA splicing The removal of introns and the ligation of exons from precursors of RNA to form mature RNA.RNA world A theoretical time early in evolution in which RNA molecules served both as the genetic material and as catalysts for biochemical reactions.RNA-induced silencing complex(RISC)An assembly of specific proteins that facilitate the process of RNA interference.Rossmann fold A common nucleotide-binding domain in proteins that is made up of four  helices and a sheet of six parallel  strands.rotenone A plant toxin that inhibits electron transfer in the NADH-Q reductase complex;used as a fish and insect poison.S

S-adenosylmethionine(SAM)An activated methyl donor that consists of an adenosyl group linked to the sulfur atom of methionine.salting out A protein purification technique based on the fact that the solubility of most proteins is lowered at higher salt concentrations;consequently, different proteins will precipitate at varying salt concentrations.salvage pathway In general, a pathway that synthesizes the final product from preformed components;nucleotides can be synthesized in a salvage pathway by attaching purine bases to PRPP.Schiff base An intermediate formed when an amine reacts with an aldehyde or a ketone from a nitrogen compound analogous to a carbonyl compound;Schiff bases are intermediates in a number of enzymecatalyzed reactions.scurvy A disease caused by a deficiency of ascorbate(vitamin C), which results in the formation of unstable collagen.SDS-polyacrylamide gel electrophoresis The electrophoresis of proteins in a polyacrylamide medium;the detergent SDS renders the movement of the proteins inversely proportional to molecular weight(see also electrophoresis).second messenger A small signal molecule whose concentration changes in response to a primary messenger.secondary structure In a protein, the spatial arrangement of amino acid residues that are relatively close to one another in the linear sequence;the α helix and the β strand are both elements of primary structure.secondary transporter A transporter that uses the energy of the downhill(exergonic)flow of one ion or molecule to power the uphill(endergonic)flow of another.Also called cotransporter.semiconservative replication In the duplication of DNA, one of the strands of each daughter molecule is newly synthesized, whereas the other is unchanged from the parental DNA double helix.sequence alignment A means of determining the evolutionary relatedness of two proteins in which the two amino acid sequences are systematically aligned with respect to each other to identify regions of significant overlap.sequential model A model for explaining allosteric enzymes in which the binding of one substrate influences the substrate affinity of neighboring active sites without necessarily inducing a transition encompassing the entire enzyme.32 sequential reactions A bisubstrate reaction in which both substrates must bind to the enzyme before any product is released.Consequently, a ternary complex of the enzyme and both substrates is a reaction intermediate.SH2 domain(Src homology domain)A domain of approximately 100 amino acids that binds to phosphotyrosine residues.SH3 domain(Src homology domain)A domain that binds proline-rich stretches of polypeptide.sheet, β A common structural motif in proteins, in which two or more β strands are associated as stacks of chains, stabilized by interchain hydrogen bonds;several β strands running in the same direction form a β pleated sheet, whereas such strands running in opposite directions form an antiparallel pleated sheet.Shine-Dalgarno sequence In messenger RNA, a purine-rich region about 10 nucleotides on the 5' side of an initiator codon that pairs with the 3' end of 16S RNA in the 30S ribosomal subunit;helps to determine where translation is initiated on an mRNA molecule.sickle-cell anemia Anemia caused by a mutation in hemoglobin that promotes aggregation of the hemoglobin when oxygen concentration is low, which in turn causes the red blood cells to form sickle shapes.Such deformed cells to not remain in circulation, thus accounting for the anemia.side chain The distinctive R group bonded to the á-carbon atom of an amino acid.sigmoid Activity curves, such as for oxygen binding or enzyme activity, that show low activity with respect to the x-axis initially and then increase rapidly, thereby generating an ―S‖ shaped curve.signal peptidase A peptidase that resides in the lumen of the endoplasmic reticulum that cleaves signal sequences from nascent polypeptide chains synthesized by endoplasmic reticulum bound ribosomes.signal sequences A sequence of amino acid residues ranging in size from 13 to 36 residues, usually at the amino terminus of the nascent polypeptide chain, that marks the protein for translocation across the rough endoplasmic reticulum.simple diffusion The movement of lipophilic molecules through a membrane down their concentration gradient.small interfering RNA(siRNA)A class of small RNA molecules that bind to mRNA and facilitate its degradation.small nuclear RNAs(snRNAs)A class of small RNAs confined to the nucleus;some play a role in splicing.++++sodium-potassium pump(Na–K pump)(Na–KATPase)An enzyme that uses the energy of ATP hydrolysis to pump sodium out of the cell and potassium into the cell.Also called sodium-potassium ATPase.solid-phase method A means of synthesizing discrete peptides in which amino acids are added step-bystep to a growing peptide chain that is anchored to an insoluble matrix.Southern blotting A technique used to locate and identify a DNA fragment containing a specific sequence;a mixture of fragments is separated by electrophoresis, transferred to a nitrocellulose sheet, hybridized to a radioactively labeled DNA probe complementary to the desired sequence, and visualized by autoradiography.specific activity A measure of the activity of a protein sample relative to the amount of protein present in the sample, usually presented as activity units per milligram of protein;assessed at each step of a protein purification procedure as a measure of the effectiveness of the purification.33 sphingolipid A phospholipid whose backbone is sphingosine rather than glycerol.Spingolipids are present in all eukaryotic cells, although their concentration is highest in cells of the central nervous system.They are also prominent components of lipid rafts.sphingomyelin Common in brain tissue, a sphingolipid in which the terminal hydroxyl group of ceramide has a phosphorylcholine substituent.sphingosine An amino alcohol containing a long, unsaturated hydrocarbon chain that is a component of the phospholipid sphingomyelin as well as glycolipids;serves a role analogous to that of glycerol in phosphoglycerides.standard free-energy change The free-energy change of a reaction, when it takes place under standard conditions, in which each of the reactants is present at a concentration of 1.0 M.starch A homopolysaccharide that is a storage form of glucose in plant chloroplasts;amylopectin, the branched form of starch, has approximately one α-1,6 linkage per thirty α-1,4 linkages, whereas amylose is unbranched, composed of glucose residues in α-1,4 linkage.start codon The first codon to be translated, usually AUG.statins Inhibitors of HMG-CoA reductase that are used to lower the plasma cholesterol level of people with atherosclerosis.steroid hormones Hormones, such as androgen and estrogen, derived from cholesterol.sticky ends Complementary single-stranded ends, also called cohesive ends, produced by restriction enzymes that cleave their palindromic target sequences in a staggered fashion.stop codons A set of codons that are recognized by release factors and mark the end of translation.strand, β An extended polypeptide chain, with an axial distance of 3.5 Å between adjacent amino acids, often found in a β pleated sheet.streptomycin A highly basic trisaccharide antibiotic that causes both the inhibition of translational initiation and the misreading of mRNA in prokaryotes.stringent response In bacteria, a decrease in the rate of ribosomal and transfer RNA synthesis in response to a scarcity of amino acids.substrate A reactant in a chemical reaction.An enzyme catalyzes a single chemical reaction or set of closely related reactions, and the components of those reactions are called substrates.substrate cycle A pair of thermodynamically irreversible biochemical reactions that simultaneously produce and consume a pair of metabolic intermediates;these paired pathways may amplify metabolic signals and in some cases can also generate heat for the maintenance of temperature in tissues.Also called futile cycle.substrate-level phosphorylation The formation of ATP from ADP in which the phosphate donor is a substrate with high phosphoryl transfer potential.subunit Any of the polypeptide chains in a protein that contains more than one of such chains.subunit, 30S The small subunit of the bacterial 70S ribosome;composed of 21 different proteins and a 16S RNA molecule.subunit, 50S The large subunit of the bacterial 70S ribosome;the site of peptide-bond synthesis, it contains 34 different proteins, a 5S RNA species, and a 23S RNA species.succinate-Q reductase An integral membrane protein complex of the inner mitochondrial membrane that transfers electrons from FADH2 formed in the citric acid cycle to coenzyme Q.Also called Complex II.succinyl CoA synthetase(succinate thiokinase)A citric acid cycle enzyme that catalyzes the cleavage of the thioester bond of succinyl CoA, which is coupled to the phosphorylation of a purine nucleoside diphosphate, usually ADP.34 sucrose A disaccharide of glucose and fructose(commonly known as table sugar)that is readily transportable and stored in many plant cells.-superoxide anion(O 2˙)A reactive oxygen species that can damage many biological materials.symporter A transport system in which a molecule is carried across a membrane in the same direction as an ion, which in turn is pumped back across the membrane through active transport linked to ATP consumption.synthase An enzyme catalyzing a synthetic reaction in which two units are joined without the direct participation of a nucleotide triphosphate.synthetase An enzyme catalyzing a synthetic reaction in which two units are joined with the direct participation of ATP or another nucleoside triphosphate.T

T state The less active state of allosteric proteins, which is in equilibrium with the more active R-state.tandem mass spectrometry The utilization of two mass analyzers to determine protein sequence.Ions of proteins that have been analyzed by a mass spectrometer are broken into smaller peptide chains by bombardment with atoms of an inert gas such as helium or argon.These new fragments can be passed through a second mass analyzer for further mass characterization.Tangier disease A disease characterized by HDL deficiency, accumulation of cholesterol in macrophages, and premature atherosclerosis.Tangier disease is due to inefficient reverse cholesterol transport, resulting from a lack of a cholesterol transport protein.TATA box Found in nearly all eukaryotic genes, a promoter element giving rise to mRNA.The TATA box is centered between 30 and 90 residues downstream of the transcription start site and has the consensus sequence 5'-TATAAAA-3'.Tay-Sachs disease A disease, caused by a failure to degrade gangliosides, in which the affected infant displays weakness and retarded psychomotor skills before 1 year of age.The child is demented and blind by age 2 and usually dies before age 3.Tay-Sachs disease A heritable disorder caused by the accumulation of gangliosides due to the lack of an enzyme(α-N-acetylhexosaminidase)responsible for their degradation;clinical characteristics include weakness, mental retardation, dementia, blindness, and death by age 3.telomerase A reverse transcriptase that contains its own template;a highly processive enzyme that elongates the 3'-ending strand of a telomere.telomeres Ends of chromosomes;the DNA at the telomere consists of hundreds of repeats of a hexanucleotide sequence characteristic of the organism.template strand The strand of DNA that is complementary to the RNA transcript.tertiary structure In proteins, the spatial arrangement of amino acid residues that are far from each other in the linear sequence, as well as the pattern of disulfide bonds.tetracycline An antibiotic that binds to the prokaryotic 30S ribosomal subunit and inhibits the binding of aminoacyl-tRNA molecules to the ribosomal complex.tetrahydrofolate(tetrahydropteroylglutamate)A highly versatile carrier of activated one-carbon units.tetrodotoxin A highly potent poison from the fugu(puffer)fish that blocks the conduction of nerve impulses along axons and excitable membranes in nerve fibers, leading to respiratory paralysis.tetroses Monosaccharides that have four carbon atoms.35 thalassemias Genetic disorders characterized by the defective synthesis of one or more hemoglobin chains.thermogenin A mitochondrial membrane protein(an uncoupling protein)that plays a role in thermogenesis by forming a pathway for the flow of protons into the mitochondria, thereby generating heat without synthesizing ATP.thiamine pyrophosphate The coenzyme form of thiamine(vitamin B1), composed of a modified thiazole ring linked by a methylene bridge to a substituted pyrimidine;a cofactor in enzymatic reactions in which bonds to carbonyl carbon atoms are cleaved or synthesized.thiamine The vitamin component of the coenzyme thiamine pyrophosphate.Also called vitamin B1.thioredoxin A protein with exposed cysteines that can be reversibly oxidized and reduced;an important electron carrier in the reduction of ribonucleotides and in photosynthesis.thymidylate synthase An enzyme that catalyzes the methylation of deoxyuridylate(dUMP)to form thymidylate(TMP).Toll-like receptor(TLR)A family of receptors that recognize specific features present in most pathogens and yet not respond to materials normally present in the host.transaldolase An enzyme that transfers a three-carbon dihydroxyacetone unit from a ketose to an aldose acceptor;one of the enzymes in the nonoxidative part of the pentose phosphate pathway.transamination The transfer of an α-amino group from an amino acid to an α-ketoacid.transcription DNA-directed synthesis of RNA catalyzed by RNA polymerase.transcription factor A protein that assists RNA polymerase in the initiation of RNA synthesis;binds to a specific promoter element.transfer RNA(tRNA)The adaptor molecule in protein synthesis;contains an amino acid recognition site as well as a template-recognition site, or anticodon.transferase An enzyme that catalyzes group transfer, often employing a cofactor.transferrin A transport protein that carries iron in the blood serum.transferrin receptor A membrane protein that binds iron-loaded transferrin and initiates its entry into cells.transgenic mouse A mouse that harbors a foreign gene.Transgenic mice are a powerful means of exploring the role of a specific gene in the development, growth, and behavior of an entire organism.transition A mutation that results from the substitution of one pyrimidine for another or one purine for another.transition state A chemical species that has the highest free energy and the lowest concentration of those on the pathway from a substrate to a product.transition-state analog A compound resembling the transition state of a catalyzed reaction;such compounds are often potent inhibitors of enzyme-catalyzed reactions.transketolase An enzyme that transfers an activated aldehyde unit from a ketose to an aldose acceptor;one of the enzymes in the nonoxidative part of the pentose phosphate pathway.translation Cellular protein synthesis, so named because the four-letter alphabet of nucleic acids is translated into the different amino acids that make up proteins.transposons Mobile bacterial genetic elements that enable genes to be transferred among nonhomologous sequences.transversion A mutation in which a purine is replaced by a pyrimidine or vice versa.36 triacylglycerols(neutral fats, triacylglycerides)Glycerols that have fatty acyl chains esterified to each of their hydroxyl groups;storage form of fats.Also known as neutral fats or triglycerides.trioses Monosaccharides that have three carbon atoms.tumor-suppressor gene Genes for DNA-repair proteins that suppress tumor development when at least one copy of the gene is free of a deleterious mutation.turn, β In proteins, a structural element composed of four amino acids, in which the CO and NH groups of residue 1 are hydrogen bonded to the NH and CO groups of residue 4, respectively;such a structure forms a hairpin turn, allowing polypeptide chains to reverse their direction.turnover number The number of substrate molecules converted into product by an enzyme molecule in a unit time when the enzyme is fully saturated with substrate;equal to the kinetic constant k2(see Michaelis constant).two-dimensional electrophoresis A protein separation technique that separates proteins by isoelectric focusing in one direction followed by SDS-polyacrylamide gel electrophoresis at 90O to the direction of first separation.two-dimensional gel electrophoresis A means of analyzing a protein sample in which the sample is initially fractionated in one dimension by isoelectric focusing and is subsequently fractionated in a second dimension, perpendicular to the first, by SDS-polyacrylamide gel electrophoresis.type 1 diabetes Diabetes that results from the autoimmune destruction of the insulin-secreting  cells in the pancreas and usually begins before age 20.Type 1 diabetes is also referred to as insulin-dependent diabetes, meaning that the affected person requires the administration of insulin to live.type 2 diabetes The most common metabolic disease in the world, which is characterized by insulin resistance.Type 2 diabetes typically arises later in life than type 1 diabetes and its appearance is correlated with obesity.tyrosine kinase A kinase that catalyzes the transfer of a phosphoryl group from ATP to the hydroxyl group of tyrosine.U

ubiquitin Present in all eukaryotes, a small, highly conserved protein that, when attached to another protein, targets it for proteolytic destruction.ultracentrifugation High-speed centrifugation used to separate biomolecules and determine their masses.uncoupling protein A mitochondrial membrane protein that plays a role in thermogenesis by forming a pathway for the flow of protons into the mitochondria, thereby generating heat without synthesizing ATP.Also called thermogenin.unfolded protein response A signal pathway triggered by ER stress that consists of several steps.First, general protein synthesis is inhibited so as to prevent more proteins from entering the ER.Second, chaperone synthesis is stimulated.Third, misfolded proteins are removed from the ER and are subsequently delivered to the proteasome for destruction.Finally, if the described response fails to alleviate the ER stress, apoptosis is triggered, which ultimately leads to cell.uniporter A class of carriers able to transport a specific species in either direction governed only by concentrations of that species on either side of the membrane.urea cycle A cyclic pathway that converts excess ammonia into urea for secretion;the first metabolic pathway to be discovered.37 ureotelic Refers to organisms in which excess ammonia is converted into urea and then excreted;most terrestrial vertebrates are ureotelic.uricotelic Refers to organisms in which excess ammonia is converted into the purine uric acid for secretion;birds and terrestrial reptiles are uricotelic.uridine diphosphate glucose(UDP-glucose)The activated form of glucose used in the synthesis of glycogen;formed from glucose 1-phosphate and UTP.V

van der Waals interaction The attraction between two molecules based on transient electron asymmetry around an atom that induces a complementary asymmetry in a nearby molecule.vector A DNA molecule that can replicate autonomously in an appropriate host organism.Vectors are designed to enable the rapid, covalent insertion of DNA fragments of interest.virus A complex of protein and nucleic acid that can penetrate a cell and replicate itself by co-opting the host's metabolism and employing its own as well as the host's gene products;the smallest organism known.vitamin A A fat-soluble vitamin that is the precursor of the light-sensitive pigment retinal and the signal molecule retinoic acid, an activator of certain transcription factors.Also called retinol.vitamin B12(cobalamin)A prosthetic group, consisting of a cobalt atom, a corrin ring, and deoxyadenosine, that plays a role in intramolecular rearrangements, methylations, and reductions of ribonucleotides to deoxyribonucleotides.Also called cobalamin.vitamin D A fat-soluble vitamin that plays a role in the regulation of calcium and phosphorus metabolism;deficiencies in vitamin D lead to the impairment of bone formation.vitamin E Protects unsaturated membrane lipids from oxidation.Also called α-tocopherol.vitamin K A fat-soluble vitamin required for blood coagulation.vitamins Organic substances required in trace amounts for a number of essential biochemical reactions.VLDLs(very low density lipoproteins)Lipoprotein particles, stabilized by apolipoproteins B-100 and E, that transport excess endogenous triacylglycerides and cholesterol from the liver to other tissues.voltage-gated channel A transmembrane channel that is opened by membrane depolarization;the sodium and potassium channels of axon membranes are good examples.W

Watson-Crick helix See B-DNA helix.western blotting An immunoassay technique used to detect a specific protein in a cell or in body fluid.A sample undergoes electrophoresis in an SDS-polyacrylamide gel, the resolved proteins are transferred to a polymer sheet, and then an antibody specific for the protein of interest is incubated with the blotted sample;other antibodies or radioactive markers may then be used to help visualize the desired antigen-antibody complex.X

x-ray crystallography A technique for determining the three-dimensional structure of protein crystals at atomic resolution by examining the diffraction pattern of x-rays striking the crystal.Y

yeast artificial chromosome(YAC)A DNA molecule that can be used to clone DNA inserts ranging from 100 to 1000 kb in length;contains a centromere, an autonomously replicating sequence, a pair of telomeres, selectable marker genes, and an insertion site for the sequence to be cloned.Z

Z-DNA A left-handed double helix in which the backbone phosphates zigzag;can be formed by oligonucleotides with alternating sequences of purines and pyrimidines.zwitterion A dipolar ion(from the German zwitter, “between”);at neutral pH, amino acids have a protonated amino group and a dissociated carboxyl group and are therefore zwitterions.zymogen A catalytically inactive precursor of an enzyme.39

第二篇：管理学原理练习题及其答案(精)

管理学原理练习题及答案

1、在管理学的发展史上,许多中外学者从不同的研究角度对管理做出了不同的结实,其中认为“管理就是决策”的管理学家是(美国管理学家赫伯特.A.西蒙

2、组织行为学的研究层次包括(上层、中层与下层

3、以持续改进为主要特点的全面质量管理理论产生于(美国通用电气公司

4、容器制造商、软饮料生产企业和啤酒经销商经常处于(简单和稳定的环境/不确定性很低的环境中

5、企业文化可以分为多个层次,其中诸如厂容、厂歌、产品形象等所反映的是(表层的企业文化

6、泰罗认为工人和雇主双方都必须来一次(心理革命

7、妨碍目标得以实现的因素,称为(限定因素

8、首先提出“目标管理和自我控制”的学者是(德鲁克

9、实现控制工作的依据是(控制标准、控制机构和人员

10、将决策分为经验决策和科学决策所依据的分类标准是(运筹学

11、主张把管理人员看成信息中心的管理学派是(沟通(信息中心学派

12、运营预算中最基本和最关键的是(销售预算

13、传统的程序化决策技术中最普遍和最为盛行的技术是(惯例

14、最能明白地显示出管理的基本特征的主要职能活动是(计划工作

15、马克思主义关于管理问题的基本观点是(管理的两重性

16、按控制原因和结果分类,可把控制

工作分为(直接控制和间接控制

17、预测方法中的“移动平均法”属于(时间序列分析法

18、层次划分主要解决的组织问题是(管 理宽度问题

19、组织中合法的权利属于(职权 20、目前最高级的管理信息系统是(专 家系统

21、从纵向上充实工作内容的职位设计 做法是(职位丰富化

22、多线性组织结构又称为(职能型组 织结构

23、通常所说的指挥权是指(直线职权

24、成功履行管理职能最基本的要求是(强烈的管理愿望

25、为使激励取得效果,管理者应做到（1、坚持物质利益原则

2、坚持按 劳分配原则

3、随机制宜,创造激励

条件

4、以身作则,发挥榜样的作用

26、有利于促进职权分散的情形是(统 计技术、会计控制方法、计算机技

术等各方面的进展

27、群体(团队的发展一般经历四个 明显的阶段,它们是(形成阶段、震荡阶段、规范、执行阶段

28、根据美国管理学家朱兰的观点,引 入变革最重要的规则是(使受到变 革影响的人们参与变革的计划与实 施

29、自发型团队又称为(工作团队 30、下列人物中,提出了决策的“满意” 标准的是(西蒙

31、学习与研究管理学的总的方法论指

导(马克思主义的唯物辩证法

32、在实际工作中,实际上不存在纯粹 的(职能型组织结构

33、所谓授权,是指(上级委授给下属 一定的权力,使下级在一定的监督 之下,有相当的自主权、行动权

34、依据科学管理理论,企业管理的首 要职责是(标准化操作方法的制

定

35、总的来说,管理者应(符合活性化 化、年轻化的要求

36、最早提出全面质量管理概念的国家 是(美国

37、预测方法中的“德尔菲法”属于(直 观法

38、部门划分最为普遍的一种方法是(按 职能划分部门

39、比较普遍采用的评价管理者职位的 分值定级法是(“指示图表”个人 能力分析法

40、根据英国伍德沃德的研究,在大批 量或集中生产场合,组织结构常常 趋向于(机械式结构

41、致力于获得分销商的所有权或对其 加强控制的战略类型是(前向一体 化

42、将计划分为使命、目标、战略、政

策、规则、程序等所依据的分类标 准是(计划的表现形式

43、主要靠人的经验和中和分析能力进 行预测的方法是(直观法

44、以下关于管理环境的选项中,不确 定性最低的是(简单和稳定的环境

45、预算也被称为(“数字化”的计划

46、在实施管理突破时,论证其必要性 的环节通常由(中层管理者来完 成

47、一般来说,适于采用损益控制法的 企业的组织结构类型是(分权制或 事业部制

48、提出随机制宜理论的管理学家是(菲德勒

49、通过惩罚来影响别人的行为的能力 称为(强制的权力

50、管理信息系统可以用下面哪一种英 文缩写来表示(MIS

51、管理的载体是(组织

53、人为没有一成不变的、普遍使用的 “最好的”管理理论和方法的是(权 变理论

54、一个管理系统要达到提体内动态平衡,必须具有的机制是(信息反 馈

55、如果组织环境的构成要素变化很小, 我们称为(稳定环境

56、在马斯洛的需要层次理论中,最高 需求是(自我实现的需求

57、被公认为管理过程学派的创始者是(法约尔

59、制定战略的实质是(为了获取相对 于竞争对手的持久的竞争实力地位 和竞争优势

61、霍桑实验的四个结论中对职工的定 性是(职工是“社会人”

62、计划赶不上变化是现实中经常出现 的现象,故计划需要进行调整设置 甚至重新编制计划,这遵循的原理 是(改变航道原理

63、专著于某个特殊的细分时常提供产 品和服务的战略称为(重点集中战 略

64、对于比较愿意采取非正式和口头的 沟通方式的人属于(目标导向的人 65、强调在制定计划时要留有余地,不 能满打满算的计划工作原理是(灵 活性原理

66、提出“合理性”决策标准的管理学 家是(哈罗德.孔茨

68、组织中主管人员监督管辖其直接下 属的人数越是适当,就越是能保证 组织的有效运行,这体现了组织工 作的(管理宽度原理

69、自我表现管理团队和工作团队相比, 具有更高的自主性是因为(自我表

现管理团队要求更多的事前计划、支持结构以及培训系统

70、董事会的主要职能是（1、受托管理

2、决策企业公司的目标

3、挑选总

经理

4、核实计划与检查成果

5、批 准预算

6、维持公司长期稳定

7、决 定利润分配

8、通过有见解的咨询来 检查计划与经营情况

71、六西格玛管理最早起源于(美国摩 托罗拉公司

72、被称为决策“硬技术”的决策方法 是指(计量决策方法

73、以一个管理者的要求来考评管理者 最合适的标准是(管理的基本原理 74、限定因素指的是(妨碍目标得以实 现的因素

75、卓越绩效模式首先产生于(日本 76、某烟厂生产企业新并购了本省最大 的烟丝生产企业,这种战略通常称 为(后向一体化

77、在实践中,评价管理者职位最常用 的方法是(时距判定法

78、在进行口头传递信息时,每传达一 次大概要损失信息的(30% 79、在各种财务比率中,财务成绩的最 佳衡量尺度是(资本金利润率

80、可称为广义的电子商务是(SCM、ERP、CRM

二、1、目前典型的网络化管理信息系统的体 系结构包括什么?答:客户机、服 务器和主机。

2、战略管理的特性有哪些?答:

1、系 统性

2、长远预见性

3、对外抗争性

4、灵活应变性。

3、正式沟通的方式包括哪几种?答:正 式沟通有下向、上向、横向、外向

沟通等几种方式。

4、现代的程序化决策技术几乎全部体现 为什么?答:现代的程序化决策技 术,几乎可以全部包含在“运筹学” 和“管理信息系统”这两种技术和 手段的体系中。

6、计划工作的基本特征有什么?答:目 的性、主导性、普遍性、经济性。

7、目前在组织中应用最广泛的反馈控制 方法有哪几种?答:财务报告分析;标准成本分析;质量控制分析;工 作人员成绩评定。

8、在团队形成和发展的过程中包括的重 要工作有哪些?答:任务型工作和 维护型工作。

9、根据职位特征模型,决定工作的意义 的变量有什么?

10、管理的两重性反映的是什么?答: 必要性和目的性。

11霍桑实验可以分为哪四个阶段?答:

1、工厂照明实验

2、继电器装配室

实验

3、大规模访问与普查

4、电话 线圈装配工实验。

12、委员会管理的缺点有什么?答:耗 费时间和成本高、妥协与犹豫不决、职责分离、一个人或少数人占支配 地位。

13、一般来说,管理学具有的特点有哪 些?答:一般性、多科性、历史性、实践性。

14、通常我们把各种激励理论归结为什 么?答:激励内容理论、激励过程理论 和行为改造型激励理论。

15、董事会的主要职能有什么?答:

1、受托管理

2、决策企业公司的目标

3、挑 选总经理

4、核实计划与检查成果

5、批 准预算

6、维护公司长期稳定

7、决定利

益分配

8、通过有见解的咨询来检查计划 与经营情况

16、具体来说,选聘管理人员的条件有 什么?答:总的说来,管理者应该德才 兼备,符合革命化、知识化、专业化、年轻化的“四化”要求。具体说来,就 是要看候选人是否具有管理愿望,是否 具有管理能力或管理的本领。

17、明确职务的方法通常有什么?答:

1、比较法

2、职务系数法

3、时距判定法

18、在激励强化理论中,管理者可以用 来改变下属行为的措施有什么?答:

1、积极强化

2、惩罚

3、消极强化或逃避性 学习

4、消失

19、影响管理宽度的因素有哪些?

1、管 理者与其下属双方的能力

2、面对问题的 种类

3、组织沟通的类型及方法

4、授权

5、计划

6、组织的稳定性也影响着管理

宽度

20、沟通联络中的障碍有什么?答:主 观障碍、客观障碍、沟通联络方式的障 碍

21、在人员配备中,从外部招聘可能出 现的结果?答:使组织处于停顿状态。

22、管理方格图中9.9型管理(战斗集 体型管理的特点有什么?答:是管理 者无论对人员还是对生产都表现出最大 可能的关心,他们把组织的下需要与个 人的需要紧密的结合起来是真正的“集 体的主管者”。

23、控制包括的步骤有哪些?答:拟订 标准、衡量成效、纠正偏差

24、关于决策有效性的标准的代表性观 点有什么?答:有三种代表性的观点, 也就形成了三种决策的类别,即最优决 策(理性决策、满意决策(有限理性决 策和合理决策。

25、通常把系统开发过程分为哪几步过 程?答:1.系统分析2.系统设计3.系统 实施

26、组织内职权的基本类型有哪些?答: 直线职权、参谋职权、职能职权

28、现代管理理论的主要代表学派有哪 几个?答:

1、管理过程学派

2、社会合 作学派

3、经验或案例学派

4、人际关系 行为学派

5、群体行为学派

6、社会技术 系统学派

7、决策理论学派

8、沟通(信 息中心学派

9、数学(“管理科学”学 派

10、权变理论学派。

29、企业文化的层次可以分为哪几层? 答:表层、中层、深层。

30、采用防守型战略企业的组织结构常 常表现的状况?答:常常表现为:高耸 型,职权相对比较集中,管理宽度比较 窄,倾向于按照职能来进行组织。

31、影响管理道德的因素有哪些?答:管理

者所处的道德阶段、管理者的个人特征、组织结构、组织文化、道德问题的强度。

32、越是组织的上层主管人员,所作出 的决策越倾向于什么?答:非程序化的、战略的、科学的、非肯定型的决策。

33、古典管理理论的代表人物有?泰罗、法约尔、马克斯.韦伯

34、沟通过程中取得成效的关键环节有哪些?答:沟通主体、编码、媒体、译码、作出反应、反馈。

35、在激励需求理论中,麦克莱兰人为人的基本需要有什么?答:成就、权力、社会需要

36、从管理学的角度看,组织的目标具有独特的属性,通常包括什么?答:目标一定要具体明确;可以度量或测量;可以实现;目标之间相互关联;时间限定。

37、管理是一种什么现象?答:是一种文化现象和社会现象。

三、名词解释

1、管理学:管理学是一门系统的研究管理的普遍规律、基本原理和一般方法的科学。

2、需要层次理论:是美国心理学家亚伯拉罕.马斯洛提出的,是以人类的需求是以层次的形式出现的,由低级的需求开始逐级向上发展导到高级需求。

3、霍桑试验:1924—1932年间,美国国家研究委员会和西方电气公司合作进行了一项研究,由于研究是在西方电气公司的霍桑工厂进行的,因此后人称之为霍桑实验。

4、社会人:职工受到社会和心理的影响,生产效率主要取决于职工的积极性,取决于职工的家庭和社会生活以及企业中人与人之间的关系所以职工是社会人。

5、沟通:指将某一信息(或意思传递给客体或对象,以期取得客体作出相应反应效果的过程。

6、经济人:又称理性—经济人,也称实利人,它认为人的一切行为都是为了最大限度的满足自己的利益,工作动机是为了获得经济报酬。

7、管理突破:是实现控制工作的第二个目的,是指通过解决组织的慢性问题,增强组织素质的有组织的活动过程。

8、职位设计:就是将若干工作任务组合起来构成一项完整的职位。

9、预测:指对未来环境所作出的估计。

10、企业的核心能力:是竞争对手无法模仿的能力,是企业获得竞争优势的关键。

11、领导工作:指对组织内每个成员(个体和全体成员(群体的行为进行引导和施加影响的活动过程。

12、移情作用:一个人将自己的意识以想象力投射在他人身上的能力。正如通常所说的,就是将自己置于别人的地位、模拟他人的感情、意见与价值观念的能力。

13、系统:指:由相互作用和相互依赖的若干组成部分结合而成的,具有特定功能的有机整体,系统本身又是它从属的一个更大系统的组成部分。从管理的角度看有两个含义:

一、是指系统是一个实体

二、是指系统是一种方法或手段。14管理道德:指规定行为是非的惯例或原则。

15、社会责任:指组织在遵守、维护和改善社会秩序、保护增加社会福利等方面所承担的职责和义务。

16、组织结构:是组织中划分、组合和协调人们的活动和任务的一种正式的框架,表现为组织各部分的排列顺序、空间位置、聚集状态、联系方式和相互关系。

四、简答题

1、管理的基本特征是什么?答:

1、管 理是一种文化现象和社会现象

2、管理的 主体是管理者。

3、管理的任务职能和层 次

4、管理的核心是处理好人际关系。

2、简述目标管理的特点。答:

1、目标 管理是参与管理的一种形式

2、强调自我 控制

3、促使下放权力

4、注重成果第一 的方针。

3、组织工作的原理有那些?答:

1、目 标统一原理

2、分工协作原理

3、管理宽 度原理

4、责权一致的原理

5、集权与分 权相结合原则

6、稳定性与适应性相结合 的原理。

5、计划工作的原理有哪些?答:

1、限 定因素原理

2、许诺原理

3、灵活性原理

4、改变航道原理

6、最优决策的条件有哪些?答:

1、问 题清晰明确

2、目标单一明确(利润最大 化

3、所有方案已知

4、偏好清楚、一 致、稳定

5、没有成本时间约束。

7、简述扁平结构的优点?答:扁平结构 有利于缩短上下级距离,密切上下 级之间的关系,信息纵向流通快, 管理费用低,而且由于管理宽度大, 被管理者有较大的自由性和创造 性,因而有满足感,同时也有利于 选择和培训下属人员。

8、管理者应怎样才能达到有效授权? 答:

1、要有善于接受不同意见的态度

2、要有放手的态度

3、要允许别人犯错误

4、要善于信任下级

5、要善于适度控制。

10、简述霍桑试验的结论?答:

1、职工 是社会人

2、企业中存在着非正式组织

3、新型的领导能力在于提高职工的满足度

4、存在着霍桑效应。

11、简述学习型组织的特点?答:要有 领导远见、要讲求战略、组织结构应该 是扁平或水平化、信息在组织内分享、以及要有强的组织文化。

六、论述

1、有效沟通的要求。答:

1、表达清楚

2、传递准确

3、避免过早评价

4、消除下级人员的顾虑

5、管理者积 极进行沟通

6、对情报沟通过程加 以控制。(请同学们自己适当阐述

2、结合实际论述企业应怎样做好激励 工作。答:从两个方面进行论述，一、从激励的方式上:

1、思想政治 工作上

2、奖励以及奖励的要求上

3、职工参加管理

4、工作内容丰富

化

5、建立和健全规章制度。

二、有效的激励要求:

1、坚持物质利益 原则

2、坚持按劳分配的原则

3、随 机制宜,创造激励条件

4、以身作 则,发挥榜样的作用。(请同学们根 据知识点适当阐述。

3、论述团队在各阶段的特点及如何有 效管理团队过程。答:分四个阶段:

1、形成阶段,在此阶段通常要阐述 其目标,确定每个成员的角色,以 及制定科接受行为的规则

2、震荡 阶段,在此期间,团队任务的真实 情况已完全理解

3、规范,在此阶 段关注个人问题转变为关注实现与 团队相关的挑战,个人已融合到团 队中。

4、执行阶段,在此阶段已经 成熟为一个具有高度凝聚力的整 体。让团队成员发挥各自的作用积 极参与和降低时间浪费;让团队成 员更多参与和协作的另一种方法是

在更小的群体中从事活动;在解决 重大问题时应采用协商决策;在团 队建设中可能会出现一些冲突或问 题,冲突的解决方案应体现团队的 最佳利益,团队成员应采取非评判 性的态度倾听团队的讨论和新观 念,应通过定期的畅谈心思或给予 反馈来表示群体感受。

七、案例:

1、某宾馆经理接到处职工王大成的报 他觉得问题不太清楚,就作了一番 调查,事实是王大人的母亲患病住 院,他母亲想喝鸡汤,由于王白天 上班,晚上去医院陪母亲,连去市 场买鸡的时间都没有,在这种情景 下,他在餐厅里偷了一只鸡,犯了 错误,经理了解了情况以后,批准 了餐厅对王作记大过一次、扣发当 月奖金,然后带着慰问品去医院看

望王的母亲,并对他母亲说“王大 成在工作中表现很好,在家里对你 也很孝顺,他是你的好儿子。”患病 的母亲含笑听着,次日,经理找到 王大成谈话,先肯定他工作好,接 着又指出偷公家东西是十分错误 的,并征求其对处分的想法。王大成对这种赏罚分明,合情合理 的处理十分感动,并表示自己错了, 愿意接受这种处分。这时,经理离 开座位说“你母亲生病半个多月, 我们都不知道,没有给予关心,我 们很对不起你。”说后,经理毕恭毕 敬地向王大成鞠了一个躬。问题:(1从管理与道德的关系,分析王大成 的行为。

(2评价经理处理这件事的做法。答:分析如下:

一、道德是指规定行为

是非的惯例或原则。王大成的行为属于 道德发展的第三个阶段表现为个人做出 的明确的努力,摆脱了所属团体或社会 权威,他的行为对于他自己来说是违背 了自己的道德原则。

二、经理的行为是 符合道德,除了由管理者所处的道德阶 段影响之外,还受经理的个人特征、组 织结构、组织文化以及道德问题的强度 等影响。经理在组织文化的内容和力量 也会影响到道德行为,他对冲突的高度 宽容的文化有较高的道德标准。他对所 面对的问题从管理者的角度处理的恰如 其分。

2、齐鲁石化公司是一个现代石油化工生 产的企业,由于这种行业具有特殊性和 危险性,公司一开始就实行从严从实管 理,制定岗位操作要求,实行公司、厂 两级的检查和奖惩制度。

1990年7月,公司所属烯烃厂裂解一班

工人提出“自我管理,让领导放心”的 口号,并提出“面检”活动,并细化为 一套可操作的行为准则,这就是(1工 作职责标准化,(2专业管理制度化,(3 现场管理定量化(4岗位培训星级化(5 工作安排定期化,(6工作过程程序化(7经济责任和管理责任契约化(8 考核奖惩定量化(9台帐资料规范化,(10管理手段现代化。

公司开展“信的过”活动,是企业基层 以及整个企业的管理水平有了显著提 高,主要表现在:(1职工的主人翁意识普 遍增强,实现了职工从 “我被管理”到“我来 管理”,群众性从严管 理蔚然成风。

(2基层建设方面明确了 由专业管理制度、管理

人员职责范围和工作 标准、班级岗位十项规 章制度等三方面构成, 使基层管理水平有了 明显提高。

(3星级管理使职工主动 学技术、技能,努力成 为多面手,对管理装置 工艺流程全面了解,提 高了处理本岗本系统 突发事件的应变能力。事故发生率大幅度降 低。

(4企业经济效益显著提 高。问题:(1齐鲁石化的“信得过” 管理采用了哪些管理 的基本方法?

(2从齐鲁石化例子,分析 企业应如何坚持以人 为中心的管理。

答:分析如下:

一、采取的方法为:商 议式的管理方法和集体参与的管理方 法。

二、企业应该根据自己具备的条件 来进行以人为中心的管理,看领导者处 于那种情况,如处于最有利和最不利的 中间情况下采用“以人为中心”的宽容 型领导方式、效果较好。如果领导者不 为人们所欢迎而必须采用机敏手段的情 况下“以人为中心”的领导方式可获得 较好的成效。在领导为下属所欢迎而任 务却没有明确规范的情况下这种领导方 式也能具有实效。

以上题目仅供参考！请把课本 上每章后思考题仔细复习,主要 看教材复习,考试不要空卷

第三篇：句子成分练习题(精__带答案)

长江三峡[曾经]留下〈过〉（许多人的）梦。（我家的）猫 [最]怕 陌生人。

祖父 [正在] 找（五十年前）的照片。（我国的）石拱桥 有（悠久的）历史。[一大早]，（勤奋的）同学们[就[安静地]坐〈在教室里〉

车间[已经]完成了(全年的)任务。（薄薄的）轻雾 浮起<在池塘里>。乔家[忽而]遭了(一场很大)的变故。我[已经]读<过><两遍>了。天气[比屋子里]冷得<多>了。

(绿色开花的)植物 有(庞大的)根系。（会变色的）花[很]多。

石拱桥[在世界桥梁史上]出现〈得比较早〉。（统筹）方法，是（一种安排工作进程的数学）方法。

（全体）同学[都]做〈完〉了（语法）作业 今天星期六。今天是星期六。说话[要]简洁〈一些〉。长江三峡[曾经]留下〈过〉（许多人的）梦。[窗外]，细雨[烟似的]飘散<着>。（鲁迅《一面》）[这时候]，(我的)脑里[突然]闪<出>(一幅)(神异的)图画<来>。

（年轻）的我们[一定][要]学<好>（科学）（文化）知识。

[昨天]，(全班)同学‖〔都〕做〈完〉了(语文)作业。

鲁班[从中]得到启发。

蔡伦 出生<在一个贫苦的铁匠家里> 鲁班 是[我国古代][春秋时期][一位][著名的][建筑]工匠。（那个时候的）（社会）生产力[还][十分]落后。鲁班 接受[了]（一项大的建筑工程）任务。他[非常诚恳地]征求（大家的）意见。秋天比春天[更]富有（欣欣向荣的）景象。张思德同志[永远]是（我们学习的）榜样。汽车[在[望不到边际的]高原上]奔驰。

[在长期的奋斗中]，我[一向]过着（朴素的）生活。

峰峦[刚刚][从黑夜中]显露出（一片）（灰蒙蒙的）轮廓。

（淡淡的）朝阳[刚][把树梢]照亮。

（豆大的）汗珠[不停地][从脸上直往下]落。他[踉踉跄跄地][从外地]赶回（久别的）家乡。（我们村里的）农民[往冻土上]铺了（一层）麦秸。

（已经上了岸的）勇士[乘机][俯身]冲了上去。

小学校显得[那样]幽静而又神秘。

心里[突然]感到（万分）沉重。他[推开门][走进去]站在桌子前。连长 命令 我们<马上休息>。

祥林嫂 叫 阿毛[坐在门槛上剥豆]。陈然 高兴<极了>！东西[就]在（这）（口）井 <里>！

（一个）青年 躺[在]（石制的）手术台<上>。（皇帝的）衣服[从来]没有获得过（这样的）赞美！

他[快乐的][简直][要]跳<起来><了>！《东方红》 是（全国）（几万万人民的）心声。（蹲着的），（坐着的），（站着的）都有！[自从处死了伪村长]，敌人[疯狂的][进行]报复！

[一九一六年夏天]，雷锋[到佳木斯]执行任务！[为了保密]，（党组织的）（几个）领导人 看了[都] <毁掉><了>！

（几个月的）监狱生活，使 陈然 增长了（许多）（地下斗争的）经验！（难翻的）老界山，（被我们这样笨重的）队伍 战胜<了>！

（万丈）高楼（平地）起！我们 学习（白求恩同志）（毫不利己专门利人的）精神！他[躺在床上][呼呼的] <睡着了>！他们所处的环境比前一代人 好<得多>！

（我的）祖母[曾经][常常][对]我说，白蛇娘娘[就]（在）（这）塔底下！

白杨树[实在]是<不平凡的>！我 赞美 白杨树！长江三峡曾经留下过许多人的梦。我家的猫最怕陌生人。

祖父正在找五十年前的照片。我国的石拱桥有悠久的历史。

一大早，勤奋的同学们就安静地坐在教室里认真地复习各门功课

车间已经完成了全年的任务。薄薄的轻雾浮起在池塘里。乔家忽而遭了一场很大的变故。我已经读过两遍了。天气比屋子里冷得多了。

绿色开花的植物有庞大的根系。一切生物都离不开食物。会变色的花很多。

石拱桥在世界桥梁史上出现得比较早。

统筹方法，是一种安排工作进程的数学方法。一斤苹果五角钱。

小李这个人性格非常好。爷爷一句话都没说。

全体同学都做完了语法作业。今天星期六。今天是星期六。说话要简洁一些。

长江三峡曾经留下过许多人的梦。窗外，细雨烟似的飘散着。他身体健康。长颈鹿脖子很长。

这时候，我的脑里突然闪出一幅神异的图画来。

年轻的我们一定要学好科学文化知识。昨天，全班同学都做完了语文作业。鲁班从中得到启发。

蔡伦出生在一个贫苦的铁匠家里。

鲁班是我国古代春秋时期一位著名的建筑工匠。

那个时候的社会生产力还十分落后。鲁班接受了一项大的建筑工程任务。他非常诚恳地征求大家的意见。秋天比春天更富有欣欣向荣的景象。张思德同志永远是我们学习的榜样。汽车在望不到边际的高原上奔驰。

在长期的奋斗中，我一向过着朴素的生活。峰峦刚刚从黑夜中显露出一片灰蒙蒙的轮廓。淡淡的朝阳刚把树梢照亮。

豆大的汗珠不停地从脸上直往下落。他踉踉跄跄地从外地赶回久别的家乡。我们村里的农民往冻土上铺了一层麦秸。已经上了岸的勇士乘机俯身冲了上去。小学校显得那样幽静而又神秘。心里突然感到万分沉重。他推开门走进去站在桌子前。连长命令我们马上休息。

祥林嫂叫阿毛坐在门槛上剥豆。

陈然高兴极了！东西就在这口井里！一个青年躺在石制的手术台上。

皇帝的衣服从来没有获得过这样的赞美！他快乐的简直要跳起来了！

《东方红》是全国几万万人民的心声。蹲着的，坐着的，站着的都有！

自从处死了伪村长，敌人疯狂的进行报复！一九一六年夏天，雷锋到佳木斯执行任务！为了保密，党组织的几个领导人看了都毁掉了！

几个月的监狱生活，使陈然增长了许多地下斗争的经验！

难翻的老界山，被我们这样笨重的队伍战胜了！

万丈高楼平地起！

我们学习白求恩同志毫不利己专门利人的精神！

他躺在床上呼呼的睡着了！

他们所处的环境比前一代人好得多！

我的祖母曾经常常对我说，柏蛇娘娘就被压在这塔底下！

白杨树实在是不平凡的！我赞美白杨树！

1、主谓谓语句：这个电影 我看过。

2、复杂宾语句链：我 看见小王在大街上边走边读书。

3、兼 语 句链：大家 选 他 当班长。

4、双宾语句：李老师 教 我们 语文。

5、连动句：他们 听了 [这个]消息[很]高兴。

6、把字句：老师[亲切地][把书]放〈到他的手中〉。

7、被字句：她[已][被北京大学]录取了。

8、存现句：我家的后面 有一个园子。

一、把下面各词填入下表：

校园 繁忙 北京 积蓄 三万 豁亮 诚实 中间 哪里 瞻仰 战场 颓唐 夜晚 二分之一 斤 朵 驾驶 那里 自己 坚固起来 大伙 政治 希望 词 类 词 语

名 词： 校园 北京 积蓄 中间 战场 夜晚 政治 动 词： 瞻仰 驾驶 起来 希望 形容词： 繁忙 豁亮 诚实 颓唐 坚固 数 词： 三万 二分之一 量 词： 斤 朵

代 词： 哪里 那里 自己 大伙

二、用符号法标出下列句子的主干。

（1）在汉江北岸，我遇到一个青年战士。（2）他被一阵哭声惊醒了。

（3）我觉得我们的战士太伟大了。（4）消息在乡下传得特别快。

（5）他们对这位来自基层的女干部和她乡人民坚持不懈的治沙精神所感动。

（6）我一直沉醉在世界的优美之中。

（7）这种魅力，就是使我终生能够在实验室里埋头工作的主要因素了。

（8）理想中的女儿应该是个淑女。（9）荔枝林深处，隐隐露出一角白屋。

（10）隔了几天，二妹从虹口舅舅家里回来。

[在苍茫的大海上]，狂风 卷集<着>乌云！（蠢笨的）企鹅，[胆怯的][把肥胖的身体]躲藏<在悬崖底下>。（那个时候的）（社会）生产力[还][十分]落后。我们是[一列]树。

春天 像(刚落地的)娃娃。

（今年的）春天 来<得太迟>。他 是（一个高而瘦的）老人。（我们）（家的)台阶<低!>。妈妈[突然] 问 我。敌人[监视]看苇塘。

（我们）家 盖<了>（新）房子。妹妹[正在] 上 小学。水珠<起来了>。

树叶儿 绿<得发亮>。我和母亲 走<在前面>。

她[又在衣袋里]摸<了半天>。（我们家的）台阶 有<三级>。

（眼前的）环境[好像]是（一个）梦。（年轻的）信客[也渐渐]变<老>。

（我国的）石拱桥 有（悠久的）历史。画眉[在树林边][婉转地]歌唱。天气[那么]暖和, [那么]晴朗。他们[轻飘飘地]浮<在水上>。［近十几年来］，(新中国)(发行的)(各种各样的)邮票［又］［大大地］丰富了(这个)(艺术)宝库。在苍茫的大海上，狂分卷集着乌云！

蠢笨的企鹅，胆怯的把肥胖的身体躲藏在悬崖底下！

那个时候的社会生产力还十分落后。我们是一列树。

春天像刚落地的娃娃。

今年的春天来得太迟。他是一个高而瘦的老人。

我们家的台阶低!妈妈突然问我。敌人监视看苇塘。我们家盖了新房子。妹妹正在上小学。水珠起来了。树叶儿绿得发亮。我和母亲走在前面。她又在衣袋里摸了半天。我们家的台阶有三级。

眼前的环境好像是一个梦。年轻的信客也渐渐变老。我国的石拱桥有悠久的历史。画眉在树林边婉转地歌唱。天气那么暖和,那么晴朗。他们[轻飘飘地]浮在水上。近十几年来，新中国发行的各种各样的邮票又大大地丰富了这个艺术宝库。

（11）勤劳勇敢的中华民族几千年来创造了光辉灿烂的文化。

（12）我国桥梁事业的飞速发展，表明了我国社会主义制度的无比优越。

（13）汽车在望不到边际的高原上奔驰。（14）写文章是交流思想、传播经验的一种方法。

（15）一个人在学习过程中有若干主要的关节。

（16）他们是一切伟大人民的优秀之花。（17）赵州桥高度的技术水平和不朽的艺术价值，充分显示了我国劳动人民的智慧和力量。（18）赵州桥的设计完全合乎科学原理。（19）统筹方法是一种安排工作进程的数学方法。

（20）一切活的生物都离不开食物。（21）我—［应该］感谢—灯光。（22）日华和月华——出现。（23）天空——布满了。（24）蟹——生存。

（25）他们—［没有］注意—关系。

（26）片面的强调读书，而不关心政治，或片面的强调政治，而不努力读书，都是错误的。（27）更让我动情的，则是从不少年轻人身上反映出的心灵美。

（28）开荒，种庄稼，种蔬菜，是足食的保证。（29）徐悲鸿以愤激的感情，用两年的时间，创作了巨幅油画《奚我后》。（30）假山的堆叠，可以说是一项艺术而不是技术。

（31）于勒叔叔把自己应得的部分遗产吃的一干二净之后，还大大占用我父亲应得的那一部分。

（32）那有节奏的歌声是和谐的、优美的。（33）我深深的明白：假如不是读过几百部真正的小说，我决不可能写出那八百个字。

（34）他的魁梧的身形，温和的脸，明净的额，慈祥的目光时时出现在会场上，课堂上，杨家岭山下的大道边。

（35）祥子喝了瓢凉水就走了出去。

（36）那壮丽的柱廊、淡雅的色调，以及四周层次繁多的建筑立面，组成了一幅庄严绚丽的图画。

（37）这是虽在北方风雪的压迫下却保持着倔强挺立的一种树。

三、用“‖”划开主谓语。

1、西起九江（不含），东至江阴，‖均是人民解放军的渡江区域。

2、在一天夜里，他‖被一陈尖叫声惊醒了。

3、纽约市通常辉煌通明的帝国大厦‖今晚熄灭了灯光。

4、袁隆平视为生命的四分田地，‖在一个星期天的早晨，还是被那些造反派扫荡一空。

5、在这样的年月里，我家‖通年没吃过白米。①管理 ②治理 ③昨天 ④推测 ⑤汉语 ⑥应

该 ⑦清楚 ⑧宽阔 ⑨减少 ⑩懒惰 A、①②⑤/③⑥⑦⑧/④⑨/⑩ B、③⑤/①②④⑥⑨/⑦⑧⑩ C、①③⑤⑦/②④⑥⑧/⑨⑩ D、①②⑤⑥⑨/③⑦⑧/④⑩

5、下列短语归类有错的一项是：（C）

A、并列：听说读写 思想感情 光荣而艰巨 轻松愉快 B、偏正：新的语法 大操场上 跟我们

6、他‖花了三十多年的时间，留意观察日、月以及各行星的运动。

7、我们的祖国‖给科学开辟了广阔的前途。

8、她‖教给了我生活的知识和革命的道理。

9、我们中华民族‖有悠久的历史和优秀的文化传统。

10、这支部队的先头连‖就匆匆占领了汽车路边一个很低的光光的小山冈。

11、我最急于告诉你们的，‖是我思想感情的一段重要经历、12、鲁镇酒店的格局，‖是和别处不同的。

13、人类历史的发展，‖与人物的活动息息相关。

14、我‖每忆及少年时代，就禁不住涌起视听的愉悦之感。

15、在汉江南岸狙击敌人的日子里，有一天他‖从阵地上下来吃饭。

四、选择题：

1、结构上全是动宾短语的一组是：（C）A、纯洁高尚 全面衡量 热烈响应 热切希望 B、灿烂异彩 重放光明 热情鼓励 放射光芒 C、分析成分 巩固胜利 战胜敌人 散发香气 D、感觉良好 完全彻底 修饰限制 搭配适当

2、谓短语充当谓语的一项是：（A）

A、他身材高大。B、他的身材高大。C、他有高大的身材。D、身材高大的就是他。

3、选出对下边句子成分分析正确的一项。（C）十几年来，延安机场上送行的情景时时出现在眼前。

A、这个句子的主语中心语是“情景”，谓语中心语是“出现”，宾语是“在眼前”。B、这个句子的主语中心语是“延安机场”，谓语中心语是“出现”，补语是“在眼前”。C、这个句子的主语中心语是“情景”，谓语中心语是“出现”，补语是“在眼前”。D、这个句子的主语是“十几年来”，谓语是“延安机场送行的情景常常出现在眼前”。

4、下面的词语，从词性上看，分类正确的一组是：（B）学 非常激动 C、动宾：复习短语 洗热水 擦干净 送我一首小诗 D、补充：热起来 做下去 疼得发紫 读两遍 摆整齐

6、选出与“愚公移山”同类结构的一项：（④）①大江两岸 ②温故知新 ③学习计划 ④襟怀坦白

7、判断下列加点的词的词性：（D）（1）我在．北京。（2）游击队员们战斗在．华北平原。（3）海燕在．高傲地飞翔。（4）我们在．党的关怀下成长。A、动词 副词 介词 介词 B、动词 副词 副词 介词 C、介词 动词 副词 介词 D、动词 介词 副词 介词

8、下列句子中用主谓短语作谓语的是：（C）A、我觉得苏州园林是我国各地园林的标本。B、冰凉的河水呛得我好难受。C、苏州园林布局幽雅。

D、人人都过幸福生活是我们美好的心愿。

9、对划线的词性分析不正确的一项是：（D）A、云霞升起来了．。（助词）B、他抑制不住工作的．热情。（助词）C、这是很．清楚的。（副词）D、我在． 房间里读书。（动词）

句子成分分析练习75题及答案

1．我 从此就看见 许多陌生的先生。2．藤野先生 总是挟着 一叠大大小小的书。（藤野与先生一起构成专用名词，不拆分）3．干事 在黑板上写 广告。

4．这位客人 直勾勾地打量着 主人的脸。5．托尔斯泰 透出 一股才气。

6．一个陌生人 把我紧紧地抱在怀中。（“把”字句，谓语和宾语倒置）7．我 默默地站在走廊上。（无宾语）

8．科学技术 是 人类本性精神的最高成就。9．这 是 一种别开生面的场面。10．在场的老年人格外兴奋、活跃。（无宾语，并省略谓语，用主补短语的形式直接成句）11．白色的丝线 拧成细细的绳子。（省略“被”字的“被”字句，宾语做主语，主语省略）12．这些节日 包含着 丰富的民俗习惯。

13．我们 喜欢倾听 大雁在沼泽中集会时的鸟叫。14．派出所的警察们 寸步不离地守卫在洞口周围。（谓语补语做宾语）15．一位手里拿着照相机的记者 一声不响地解掉了 系在自己腰里的那条结实的粗绳子。16．许多原子能发电厂 源源不断地运来 许多铅做的大箱子。19．张思德同志 永远是 我们学习的榜样。（“同志”是“张思德”的同位称呼，做同为主语）51．当时我国的地震灾害 十分频繁。（主谓短语直接成句）52．（一天），地动仪向着西方的那条龙嘴里的铜球 忽然落下。（无宾语）

53．这个神话 是 人们无法认识死海形成过程的一种猜测。

54．我国桥梁事业的飞跃发展，表明了 我国社会主义制度的无比优越。55．地中海沿岸 被称为西方文明的摇篮。（“被”字句）27．已经上了岸的勇士 乘机俯身冲了上去。（无宾语，谓语补语做宾语）28．小学校 显得那样幽静而又神秘。（同上；笨句在英语中叫表语从句）29．心里 突然感到万分沉重。（同上）

30．他 推开门走进去站在桌子前。（主谓短语直接成句，一系列动作做谓语，谓语补语做宾语）

31．连长 命令 我们马上休息。（主谓短语做宾语）

32．祥林嫂 叫 阿毛坐在门槛上剥豆。（同上）34．（因为鲁班的技艺高超），后世的建筑工匠、木匠 尊称他为“祖师”。（无宾语，谓语补语做宾语）

35．鲁班所处的时代 距现在已经好几千年了。（含有描述的主语短语直接成句，主语的同位补语做谓语）

38．鲁班 发现 这种草叶的两边都长着锯齿状的刺。40．鲁班 用锯齿状的竹片在一棵小树树干上来回拉了起来。（无宾语，谓语补语做宾语）41．鲁班 想，如果用铁片代替竹片，效果可能会更好。（句子做宾语）42．（直到今天），锯子 仍然是 木匠们干活的主要工具。43．（后来），鲁班 又陆续发明了 木刨、钻、墨斗和曲尺等许多木匠工具。44．（除去发明了许多木匠工具外），鲁班 在其他方面还有 不少创新。45．（当时），还有人 把字写在丝织的帛上。（“把”字句）47．（经过反复的试验），蔡伦 终于发明了 造纸术。

48．蔡伦 苦苦地思考着 改进的方法。

49．地球上 几乎每时每刻都在发生着 地震。50．全世界的科学家们 都在努力探索 地震灾害的规律。

75．（近几年来），父亲和我 都东奔西走地忙碌。（无宾语）

第四篇：生物化学重点名词英文缩写

生物化学英文缩写

第一章 蛋白质

氨基酸分类

1、非极性脂肪族氨基酸 Gly 甘氨酸 Ala 丙氨酸 Val 缬氨酸 Leu 亮氨酸 Ile 异亮氨酸 Pro 脯氨酸

2、极性中性氨基酸 Ser 丝氨酸 Cys 半胱氨酸 Met 蛋氨酸 Asn 天冬酰胺 Gln 谷氨酰胺 Thr 苏氨酸

3、芳香族氨基酸 Phe 苯丙氨酸 Trp 色氨酸 Tyr 酪氨酸

4、酸性氨基酸 Asp 天冬氨酸 Glu 谷氨酸

5、碱性氨基酸 Lys 赖氨酸 Arg 精氨酸 His 组氨酸

Hb 血红蛋白 Mb 肌红蛋白 PrP 阮病毒蛋白 PI 等电点 CD 圆二色光谱 NMR 核磁共振技术

第二章 核酸

cAMP 环腺苷酸

HGP

人类基因组计划 hnRNA 不均一核RNA

m7GpppN 7-甲基鸟嘌呤-三磷酸核苷 CBP 帽结合蛋白

PABP

poly（A）结合蛋白 ORF 开放阅读框 DHU 双氢尿嘧啶 ψ

假尿嘧啶核苷

mG，mA 甲基化嘌呤

snmRNA

非mRNA小RNA snRNA

核内小RNA snoRNA

核仁小RNA scRNA

胞质小RNA siRNA

小片段干扰RNA

第三章

酶

NAD

尼克酰胺腺嘌呤二核苷酸，辅酶I NADP 尼克酰胺腺嘌呤二核苷酸磷酸，辅酶II

FMN

黄素单核苷酸 FAD

黄素腺嘌呤核苷酸 LDH

乳酸脱氢酶 CK

肌酸激酶 PCR

聚合酶链反应 BAL

二巯基丙醇 PAM

解磷定

第四章 糖代谢

SGLT

Na依赖型葡萄糖转运体 GLUT 依赖一类葡萄糖转运体 G-6-P

6-磷酸葡萄糖 PEK-1 6-磷酸果糖激酶-1 PEP

磷酸烯醇式丙酮酸 FBP-2 果糖二磷酸酶-2 TAC

三羧酸循环（TCA循环）GSH

谷胱甘肽

UDPG 尿苷二磷酸葡萄糖 UDPGA尿苷二磷酸葡萄糖醛酸 PKA

蛋白激酶A

第五章 脂类代谢 FA

脂肪酸 PG

前列腺素 TX

血栓烷 LTs

白三烯 CM

乳糜微粒 FFA 游离脂肪酸

HSL 激素敏感性甘油三酯脂酶 ACP 酰基载体蛋白 VLDL 极低密度脂蛋白 LDL 低密度脂蛋白 IDL

中密度脂蛋白 HDL 高密度脂蛋白

SRS-A 过敏反应的慢反应物质 5-HPETE 氢过氧化廿碳四烯酸 PA

磷脂酸

PIP2

磷脂酰肌醇-4，5-二磷酸 IP3

三磷酸肌醇

RCDP 康-亨综合症 MVA 甲羟戊酸

SCP

固醇载体蛋白 CE

胆固醇酯

LRP

LDL受体相关蛋白 HL

肝脂酶 FC

游离胆固醇

CERP 胆固醇流出调节蛋白

LCAT 卵磷脂胆固醇脂肪酰转移酶

第六章 生物氧化 Fe-S

铁硫中心

CoQ

辅酶Q（泛醌）

F P2

黄素蛋白-2（人复合体2）Cyt

细胞色素

OSCP 寡霉素敏感蛋白 DNP

二硝基苯酚 mtDNA 线粒体DNA CP

磷酸肌酸

ROS

反应活性氧类（自由基）SOD

超氧物歧化酶

第七章

氨基酸代谢 GPT

谷丙转氨酶 ALT

丙氨酸转氨酶 GOT

谷草转氨酶 AST

天冬氨酸转氨酶 IMP

次黄嘌呤核苷酸

CPS-I 氨基甲酰磷酸合成酶I AGA

N-乙酰谷氨酸

OCT

鸟氨酸氨基甲酰转移酶 5-HT

5-羟色胺 FH4

四氢叶酸

SAM

S-腺苷甲硫氨酸 NOS

一氧化氮合酶

第八章

核苷酸代谢

HGPRT 次黄嘌呤-鸟嘌呤磷酸核糖转移酶PRPP

磷酸核糖焦磷酸 6MP

6-巯基嘌呤 MTX

甲氨蝶呤 5-FU

5-氟尿嘧啶

FUTP

三磷酸氟尿嘧啶核苷

第九章

物质代谢的联系与调节 MS

中心性肥胖 CCK

胆囊收缩素

第十章

DNA的生物合成 E.coli

大肠杆菌

dNTP

脱氢三磷酸核苷（N代表任一碱基）DNA-pol DNA聚合酶

SSB

单链DNA结合蛋白 HDP

螺旋反稳定蛋白 RF

复制因子/释放因子 PCNA 增殖细胞核抗原

CDK

细胞周期蛋白依赖激酶 hTR

人类端粒RNA hTP1

人类端粒协同蛋白1 hTRT

端粒酶逆转录酶 TT

胸苷酸二聚体

第十一章

RNA的生物合成 CTP

羧基末端结合域 Inr

转录起始子 TF

转录因子

PIC

转录起始前复合物 TPB TATA-结合蛋白

CDK-9 周期蛋白依赖性激酶9 CPSF 断裂和聚腺苷酸化特异性因子 CStF

断裂激动因子

PAP

多聚腺苷酸聚合酶 PAB II 腺苷酸结合蛋白II

第十二章

蛋白质的生物合成 rp

多种核糖体蛋白质 EF 延长因子

fMet N-甲酰甲硫氨酸 THFA N10-甲酰四氢叶酸

RBS

核糖体结合位点

PAB/PABP poly A结合蛋白 TF

触发因子 HSP

热休克蛋白

PDI

蛋白质二硫键异构酶 PPI

肽-脯氨酰顺反异构酶 POMC 鸦片促黑皮质素原 ACTH 促肾上腺皮质激素 β-LT β酯酸释放激素 α-MSH α-促黑激素

CLIP

促肾上腺皮质激素样中叶肽 SRP

信号肽识别颗粒 IFN

干扰素

第十三章

基因表达调控 AFP

编码甲胎蛋白

CAP

分解物基因激活蛋白 IPTG 异丙基硫代半乳糖苷

TAF

TATA盒结合蛋白（TBP）相关因子UAS

上游激活序列 EBP

增强子结合蛋白 bZIP

碱性亮氨酸拉链 bHLH 碱性螺旋-环-螺旋 RNP

核糖体复合物 TfR

运铁蛋白受体 IRE

铁反应元件 eIF

翻译起始因子 RBP

RNA结合蛋白 RISC 沉默复合体 dsRNA 双链RNA

第十四章

基因重组与基因工程 IS

插入序列 bp

碱基对

YAC 人工染色体载体 cDNA 逆转录DNA

第十五章

细胞信息传导 PDE

磷酸二酯酶

cGPK cGMP依赖性蛋白激酶（PKG）PLC

磷脂酰肌醇特异性磷脂酶C DAG

二酯酰甘油 PIKs

磷脂酰肌醇激酶 CaM

钙调蛋白 PP

蛋白磷酸酶 HRE

激素反应元件

GPCR G蛋白偶联型受体 PTK

酪氨酸激酶 EGF

表皮生长因子 IκB

NF-κB抑制蛋白 β-AR β-肾上腺素能受体

XLA

人类X染色体连锁低γ丢蛋白血症

第十六章

血液的生物化学 Gal

半乳糖

APP 急性时相蛋白质 GRP C-反应蛋白 IL-1 白细胞介素-1 APR 急性时相反应物 MHb 高铁血红蛋白 ALA δ-氨基-γ-酮戊酸 UPG-I 尿卟啉原I同合酶 CPG III 粪卟啉原III EPO

促红细胞生成素

第十七章

肝的生物化学 GK

葡糖激酶

MEOS 肝微粒体乙醇氧化系统 UGT 葡糖醛酸基转移酶

COMT 可溶性儿茶酚-O-甲基转移酶 GST

谷胱甘肽-S-转移酶

第二十章

癌基因

Rb基因

视网膜母细胞瘤基因

第五篇：《生物化学(乙)》必做作业答案

浙江大学远程教育学院 《生物化学（乙）》课程作业答案（必做）第二章蛋白质化学

一、填空题

1.答案：肽键氨基羧基共价键

2.答案：16% 氨基酸

20种甘氨酸脯氨酸

L-(—氨基酸 3.答案：(—螺旋β—折叠β—转角无规卷曲 4.答案：氢键离子键(盐键)疏水作用范德华力 5.答案：亚基

6.答案：颗粒表面水化膜表面带有同种电荷，二、名词解释

1.蛋白质一级结构：答案：指肽链中通过肽键连接起来的氨基酸排列顺序，这种顺序是由基因上遗传信息所决定的。维系蛋白质一级结构的主要化学键为肽键，一级结构是蛋白质分子的基本结构，它是决定蛋白质空间结构的基础。

2.肽键平面：答案：肽键不能自由旋转而使涉及肽键的6个原子共处于同一平面，称为肽单元或肽键平面。但由于α-碳原子与其他原子之间均形成单键，因此两相邻的肽键平面可以作相对旋转。

3.亚基：答案：某些蛋白质作为一个表达特定功能的单位时，由两条以上的肽链组成，这些多肽链各自有特定的构象，这种肽链就称为蛋白质的亚基。

4.变构效应：答案：蛋白质空间构象的改变伴随其功能的变化，称为变构效应。具有变构效应的蛋白质称为变构蛋白，常有四级结构。以血红蛋白为例，一分子氧与一个血红素辅基结合，引起亚基构象变化，进而引进相邻亚基构象变化，更易与氧气结合。

5.肽：答案：一个氨基酸分子的α-羧基与另一个氨基酸分子的α-氨基在适当的条件下经脱水缩合即生成肽键，多个氨基酸以肽键连接成的反应产物称为肽。

三、问答题

1．什么是蛋白质的二级结构？它主要有哪几种？各有何特征？

答案：蛋白质二级结构是指多肽链主链原子的局部空间排布，不包括侧链的构象。它主要有α－螺旋、β－折叠、β－转角和无规卷曲四种。在α－螺旋结构中，多肽链主链围绕中心轴以右手螺旋方式旋转上升，每隔3.6个氨基酸残基上升一圈。氨基酸残基的侧链伸向螺旋外侧。每个氨基酸残基的亚氨基上的氢与第四个氨基酸残基羰基上的氧形成氢键，以维持α－螺旋稳定。在β－折叠结构中，多肽链的肽键平面折叠成锯齿状结构，侧链交错位于锯齿状结构的上下方。两条以上肽链或一条肽链内的若干肽段平行排列，通过链间羰基氧和亚氨基氢形成氢键，维持β－折叠构象稳定。在球状蛋白质分子中，肽链主链常出现180°回折，回折部分称为β－转角。β－转角通常有4个氨基酸残基组成，第二个残基常为辅氨酸。无规卷曲是指肽链中没有确定规律的结构。第三章核酸化学

一、填空题

1.答案：

5′

3′ 2.答案：氢键碱基堆集力

3.答案：

dAMP

dGMP

dCMP

dTMP

AMP

GMP

CMP UMP 4.答案：

2nm

3.4nm

0.34nm

二、名词解释 1.DNA双螺旋结构：答案：大多数生物的DNA分子都是双链的，而且在空间形成双螺旋结构。DNA分子是由两条长度相同、方向相反的多聚脱氧核糖核苷酸链平行围绕同一“想象中”的中心轴形成的双股螺旋结构。二链均为右手螺旋。两条多核苷酸链中，脱氧核糖和磷酸形成的骨架作为主链位于螺旋外侧，而碱基朝向内侧。两链朝内的碱基间以氢键相连，使两链不至松散。

2.碱基互补规律：答案：腺嘌呤与胸腺嘧啶以二个氢键配对相连；鸟嘌呤与胞嘧啶以三个氢键相连，使碱基形成了配对。这种严格的配对关系称为碱基互补规律。

3.DNA变性：答案：在理化因素作用下，破坏DNA双螺旋稳定因素，使得两条互补链松散而分开成为单链，DNA将失去原有的空间结构，从而导致DNA的理化性质及生物学性质发生改变，这种现象称为DNA的变性。

三、问答题

1.比较试简述DNA、RNA在分子组成上的特点

答案：组成RNA的碱基是A、G、C、U，而组成DNA的碱基是A、G、C、T。戊糖不同之处是RNA含有核糖，而DNA含有脱氧核糖。组成RNA的基本核苷酸分别是AMP、GMP、CMP和UMP四种。组成DNA的基本核苷酸是dAMP、dGMP、dCMP、dTMP四种。DNA分子由两条反向平行并且彼此完全互补的脱氧核糖核苷酸链组成，RNA是单链核酸，会形成局部的链内配对。第四章酶

一、填空题

1.答案：ES

相同斜率的直线，Km减小

Vmax降低 2.答案：酶浓度，底物浓度，温度，pH，激活剂，抑制剂

二、名词解释

1.酶的辅助因子：答案：指结合酶的非蛋白质部分，主要有小分子有机化合物及某些金属离子。小分子有机化合物根据它们与酶蛋白的亲和力大小，又分辅基和辅酶两种。前者与酶蛋白亲和力大，后者亲和力小。辅基和辅酶在酶促反应过程中起运载底物的电子、原子或某些化学基团的作用。常见的辅基和辅酶分子中多数含有B族维生素成分。

2.活性中心：答案：酶分子中与催化作用密切相关的结构区域称活性中心。活性中心的结构是酶分子中在空间结构上比较靠近的少数几个氨基酸残基或是这些残基上的某些基团，在一级结构上可能位于肽链的不同区段，甚至位于不同的肽键上，通过折叠、盘绕而在空间上相互靠近。

3.酶原激活：答案：指无活性的酶的前体转变成有活性酶的过程。酶原激活在分子结构上是蛋白质一级结构和空间构象改变的过程。

4.同工酶：答案：能催化相同的化学反应，但其分子组成及结构不同，理化性质和免疫学性质彼此存在差异的一类酶。它们可以存在于同一种属的不同个体，或同一个体的不同组织器官，甚至存在于同一细胞的不同亚细胞结构中。

三、问答题

1.论述影响酶反应速度的因素。答案：（1）底物浓度对反应速度的影响：在一定[E]下，将[S]与v作图，呈现双曲线，当底物浓度较低的初始反应阶段底物浓度与反应速度成正比，然后处于混合级反应阶段，当底物浓度加大到可占据全部酶的活性中心时，反应速率达到最大值，即酶活性中心被底物所饱和。此时如继续增加底物浓度，不会使反应速率再增加。

（2）酶浓度对反应速度的影响：当反应系统中底物的浓度足够大时，酶促反应速度与酶浓度成正比，即ν=k[E]。

（3）温度对反应速度的影响：酶促反应速度随温度的增高而加快。但当温度增加达到某一点后，由于酶蛋白的热变性作用，反应速度迅速下降，直到完全失活。酶促反应速度随温度升高而达到一最大值时的温度就称为酶的最适温度。

（4）pH对反应速度的影响：pH对酶促反应速度的影响，通常为一“钟形”曲线，即pH过高或过低均可导致酶催化活性的下降。酶催化活性最高时溶液的pH值就称为酶的最适pH。（5）抑制剂对反应速度的影响：凡是能降低酶促反应速度，但不引起酶分子变性失活的物质统称为酶的抑制剂。按照抑制剂的抑制作用，可将其分为不可逆抑制作用和可逆抑制作用两大类。

（6）激活剂对反应速度的影：能够促使酶促反应速度加快的物质称为酶的激活剂。酶的激活剂大多数是无机离子，如K+、Mg2+、Mn2+、Cl-等。第五章糖代谢

一、填空题 1．答案：2 3 2．答案：胞液己糖激酶或葡萄糖激酶

6-磷酸果糖激酶-l 丙酮酸激酶 3．答案：线粒体糖酵解

二、名词解释

1．糖酵解：答案：葡萄糖或糖原在不消耗氧的条件下被分解成乳酸的过程，称为糖的无氧分解（或无氧氧化）。由于此反应过程与酵母菌使糖生醇发酵的过程基本相似，故又称为糖酵解（或无氧酵解）。

2．乳酸循环：答案：在肌肉中葡萄糖经糖酵解生成乳酸，乳酸经血液运至肝脏，肝脏将乳酸异生成葡萄糖，葡萄糖释放至血液又被肌肉摄取，这种循环进行的代谢途径叫做乳酸循环。3.糖异生：答案：由非糖物质转变为葡萄糖或糖原的过程称为糖异生。非糖物质：乳酸、甘油、生糖氨基酸等。糖异生代谢途径主要存在于肝及肾中。

三、问答题

1．以葡萄糖为例，比较糖酵解和糖有氧氧化的异同。答案：糖酵解和糖有氧氧化的异同见表6-1。表6-1 糖酵解和糖有氧氧化的异同 比较项目糖酵解糖有氧氧化 反应部位胞液胞液和线粒体 反应条件无氧有氧

受氢体

NAD+

NAD+、FAD 限速酶己糖激酶或葡萄糖激酶、己糖激酶或葡萄糖激酶、6-磷酸果糖激酶-l、6-磷酸果糖激酶-l、丙酮酸激酶、丙酮酸脱氢酶复合体、丙酮酸激酶。柠檬酸合成酶、异柠檬酸脱氢酶、α-酮戊二酸脱氢酶复合体。

生成ATP数

1分子G氧化分解净生成2分子ATP 净生成36或38分子ATP 产能方式底物水平磷酸化底物水平磷酸化和氧化磷酸化，后者为主 终产物乳酸

CO2和H2O 生理意义糖酵解是肌肉在有氧条件下进行收糖的有氧氧化是机体获得能量的主要途径； 缩时迅速获得能量的重要途径；是三羧酸循环是体内糖、脂肪、蛋白质三大营 机体缺氧时获得能量的主要途径；养物质彻底氧化分解共同的最终代谢通路； 是成熟红细胞获得能量的唯一方是体内物质代谢相互联系的枢纽。式；是神经、白细胞、骨髓等组织 细胞在有氧情况下获得部分能量的 有效方式。2．何谓三羧酸循环？有何特点？

答案：三羧酸循环是以乙酰辅酶A的乙酰基与草酰乙酸缩合为柠檬酸开始，经过两次脱羧和4次脱氢等反应步骤，最后又以草酰乙酸的再生为结束的连续酶促反应过程，此过程存在于线粒体内。因为这个反应过程的第一个产物是含有三个羧基的柠檬酸，故称为三羧酸循环，也叫做柠檬酸循环。

三羧酸循环特点：①在有氧条件下进行；②在线粒体内进行；③有两次脱羧和4次脱氢；④受氢体是NAD+和FAD；⑤循环1次消耗1个乙酰基，产生12分子ATP；⑥产能方式是底物磷酸化和氧化磷酸化，以后者为主；⑦循环不可逆；⑧限速酶是柠檬酸合酶、异柠檬酸脱氢酶和α-酮戊二酸脱氢酶复合体；⑨关键物质草酰乙酸主要由丙酮酸羧化回补。第六章脂代谢

一、填空题

1.答案：经三羧酸循环氧化供能合成脂肪酸合成胆固醇合成酮体等 2.答案：乙酰乙酸β-羟丁酸丙酮肝细胞乙酰CoA

肝外组织 3.答案：转运外源性脂肪转运内源性脂肪转运胆固醇逆转胆固醇

二、名词解释

1．必需脂肪酸：答案：机体必需但自身又不能合成或合成量不足、必须靠食物提供的脂肪酸称必需脂肪酸，人体必需脂肪酸是一些不饱和脂肪酸，包括亚油酸、亚麻酸和花生四烯酸。2．激素敏感性脂肪酶：答案：是指脂肪细胞中的三脂酰甘油脂肪酶。它对多种激素敏感，其活性受多种激素的调节，胰岛素能抑制其活性；胰高血糖素、肾上腺素等能增强其活性。是脂肪动员的限速酶。3．血浆脂蛋白：答案：血浆中脂蛋白与载脂蛋白结合形成的球形复合体，表面为载脂蛋白、磷脂、胆固醇的亲水基团，这些化合物的疏水基团朝向球内，内核为甘油三酯、胆固醇酯等疏水脂质，血浆脂蛋白是血脂在血浆中的存在和运输形式。

三、问答题

1．1分子12C饱和脂肪酸在体内如何氧化成水和CO2？计算ATP的生成。答案：12C脂肪酸氧化分解包括以下几个阶段：

（1）脂肪酸活化生成脂酰CoA

消耗2个高能键（2）脂酰基由肉碱携带进入线粒体

（3）通过5次-氧化，生成6分子乙酰CoA

生成5×5=25ATP（4）经三羧酸循环，乙酰CoA氧化成水和CO2

生成12×6=72ATP ATP生成数合计：25 + 72 － 2 = 95 另外，在肝脏乙酰CoA缩合成酮体，然后运至肝外组织，酮体重新转变为乙酰CoA，经三羧酸循环生成水和CO2。第七章生物氧化

一、填空题

1.答案：氧化磷酸化底物水平磷酸化

2.答案：每消耗1mol氧原子所消耗无机磷酸的摩尔数 2

3.答案：NADH 琥珀酸

二、名词解释

1.高能磷酸化合物：答案：生物化学中一般将水解能释放出20.92kJ/mol以上自由能的磷酸化合物称为高能磷酸化合物。

2.生物氧化：答案：有机分子如糖、脂肪、蛋白质等在机体细胞内氧化分解，生成二氧化碳和水并释放出能量的过程。

呼吸链：答案：在线粒体中，由若干递氢体或递电子体按一定顺序排列组成的，与细胞呼吸过程有关的链式反应体系称为呼吸链。第八章氨基酸代谢

一、填空题

1．答案：联合脱氨基作用转氨基作用氧化脱氨基作用转氨酶谷氨酸脱氢酶

2．答案：ALT（丙氨酸氨基转移酶）AST（天冬氨酸转移酶）磷酸吡哆醛磷酸吡哆胺 3．答案：氨基酸脱氨生成由肠管吸收的氨肾产生的氨 4．答案：FH4

嘌呤嘧啶核苷酸

二、名词解释

1．转氨基作用：答案：在转氨酶的催化下，α-酮酸与α-氨基酸进行氨基的转移，生成相应的α-酮酸与α-氨基酸的过程。体内的转氨酶有ALT和AST，其辅酶是磷酸吡哆醛和磷酸吡哆胺，内含维生素B6。

2．鸟氨酸循环：答案：即尿素合成过程，体内氨的主要代谢去路是用于合成无毒的尿素。合成尿素的主要器官是肝脏，但在肾及脑中也可少量合成。过程是氨基甲酰磷酸的合成、瓜氨酸的合成、精氨酸的合成、尿素和鸟氨酸的生成。在胞液和线粒体中进行。

3.必需氨基酸：答案：是指体内不能合成、必需由食物蛋白提供的氨基酸。主要有8种，它们是：异亮氨酸、亮氨酸、赖氨酸、甲硫氨酸、苯丙氨酸、苏氨酸、色氨酸和缬氨酸。体内不能合成，必须由食物蛋白质供给的氨基酸称为必需氨基酸

三、问答题

氨基酸脱氨基的方式有哪几种？

答案：脱氨基作用主要有氧化脱氨基、转氨基、联合脱氨基、嘌呤核苷酸循环和非氧化脱氨基作用。转氨基作用中，在转氨酶的催化下，α-酮酸与α-氨基酸进行氨基的转移，生成相应的α-酮酸与α-氨基酸的过程。体内的转氨酶有ALT和AST，其辅酶是磷酸吡哆醛和磷酸吡哆胺，内含维生素B6。

氧化脱氨基作用经脱氢、加水、放出氨。酶是谷氨酸脱氢酶，分布广，活性强，两种组织活性低（心肌和骨骼肌）。

联合脱氨基作用是转氨基作用加上氧化脱氨基作用，是氨基酸脱氨基作用的一种重要方式，也是体内生成非必需氨基酸的主要途径。在心肌和骨骼肌则通过嘌呤核苷酸循环。第十章

DNA生物合成

一、填空题

1.①严格的碱基选择②DNA聚合酶的校正功能③RNA引物的作用 2.NA

蛋白质催化端粒DNA的合成自身的RNA

二、名词解释

1.DNA半保留复制：答案：DNA复制时亲代双链DNA解开，各以每股单链为模板，利用4dNTP，经碱基互补配对，合成新的互补链。生成的两个DNA分子中各有一股链来自亲代分子，另一股为合成新链。

2.连续复制：答案：DNA复制时，新链延伸的方向为5＇→3＇，前导链的合成与复制叉行进方向一致，是连续合成；随从链合成与复制叉行进方向相反，先合成DNA单链片段，然后彼此连接成长链，此链为不连续合成。

3.引发体：答案：引物酶合成RNA引物的过程中，首先在复制起始点由许多蛋白质因子如PriA、B、C、DnaB、C、T等与引物酶结合装配成复合物，即引发体，进而催化RNA引物的合成。

4.冈崎片段：答案：随从链不连续合成的结果，生成许多带有RNA引物的DNA片段，此种合成方式由日本学者冈崎首先发现，故将该种片段称为冈崎片段。

三、问答题 1.试述参与DNA复制的过程及其重要酶类的主要功能。

答案：复制的起始：解旋解链，形成复制叉：由拓扑异构酶和解链酶作用，使DNA的超螺旋及双螺旋结构解开，形成两条单链DNA；单链DNA结合蛋白（SSB）结合在单链DNA上，形成复制叉；在引物酶的催化下，以DNA链为模板，合成一段短的RNA引物。

复制的延长：⑴聚合子代DNA：由DNA聚合酶催化，以亲代DNA链为模板，从5'→3'方向聚合子代DNA链。

⑵引发体移动：引发体向前移动，解开新的局部双螺旋，形成新的复制叉，随从链重新合成RNA引物，继续进行链的延长。

复制的终止：⑴去除引物，填补缺口： RNA引物被水解，缺口由DNA链填补，直到剩下最后一个磷酸酯键的缺口。

⑵连接冈崎片段：在DNA连接酶的催化下，将冈崎片段连接起来，形成完整的DNA长链。2.何谓DNA复制的保真性？哪些因素可保证此特性？ 答案：保真性是制复制过程中合成新链的碱基序列与模板链具有高度的互补性，使子代DNA分子的结构与亲代DNA完全相同，从而使亲代DNA的遗传信息真实不变地传递到子代DNA分子中。

复制的保真性有赖于以下因素的作用：①复制中严格的碱基选择；②DNA聚合酶的校正功能；③RNA引物的作用。

第十一章 RNA的生物合成（转录）

一、填空题

1．答案：模板链编码链编码链 2．答案：m7GpppG

poly A 3．答案：DNA

5＇

3＇

二、名词解释

1．转录：答案：在DNA指导的RNA聚合酶催化下，生物体以DNA的一条链为模板，按照碱基配对原则，合成一条与DNA链的一定区段互补的RNA链，这个过程称为转录。

2．结构基因：答案：在DNA链上，并非任何区段都可以转录，凡是能转录出RNA的DNA区段称为结构基因。

3．核心酶：答案：原核生物RNA聚合酶是由5个亚基组成的五聚体（α2ββ′σ）蛋白质，脱去σ亚基后，剩余的α2ββ′亚基合称为核心酶。

4.转录的不对称性：答案：是指以双链DNA中的一条链作为模板进行转录，从而将遗传信息由DNA传递给RNA；对于不同的基因来说，其转录信息可以存在于两条不同的DNA链上。

三、问答题

1．简述复制与转录的相似和区别。

答案：复制和转录都以DNA为模板，都需依赖DNA的聚合酶，聚合过程都是在核苷酸之间生成磷酸二酯键，新链合成都是从5′→3′方向延长，都需遵从碱基配对规律。复制和转录的区别是：通过复制使子代保留亲代全部遗传信息，而转录只是根据生存需要将部分信息表达。复制以双链DNA为模板，而转录只需单链DNA为模板；复制产物是双链DNA，转录产物是单链RNA。此外，聚合酶分别是DNA pol和RNA pol；底物分别是dNTP和NTP；复制是碱基A-T、G-C配对，转录是碱基A-U、G-C配对；复制需要RNA引物，转录不需要任何引物。

第十二章蛋白质的生物合成

一、填空题

１.答案：模板携带转运氨基酸合成蛋白质的场所 2.答案： 64 61 AUG UAA UAG UGA 3.答案：新生肽的剪切新生肽的折叠亚基的聚合脱N-甲酰基或N-蛋氨酸个别氨基酸的修饰

二、名词解释

1．蛋白质生物合成的密码子：答案：作为指导蛋白质生物合成的模板，mRNA中每三个相邻的核苷酸组成三联体，代表一个氨基酸的信息，此三联体就称为蛋白质合成的密码子。共有64种不同的密码。

2．遗传密码的摆动性：答案：密码子第３位与反密码子的第１位碱基配对有时会出现不遵守碱基配对规律的情况，称为遗传密码的摆动性。

3．多核糖体：答案：多个核糖体可以在一条mRNA链上同时合成多条相同的多肽链，称为多核糖体循环。

三、问答题

1.简述蛋白质生物合成过程：

答案：氨基酸活化后，在核蛋白体上缩合形成肽键的过程称为核蛋白体循环，循环包括： ①肽链合成的起始起始阶段在Mg2+，GTP，起始因子作用下，由核蛋白体大、小亚基，模板mRNA及蛋氨酰-tRNA共同构成起始复合体。起始密码子处于P位，mRNA上第二个密码子处于A位。

②肽链的延长在肽链延长因子，GTP，Mg2+等参与下，经过进位、转肽、移位三个步骤重复进行，肽链按遗传信息所编码的氨基酸顺序不断延长。

③肽链合成的终止和释放当肽链合成至A位上出现终止信号（UAA/UGA/UAG）时，多肽链合成终止，开始另一条肽链的合成。第十三章基因表达调控

一、填空题

1.答案：不变持续恒定 2．答案：生长发育分化

二、名词解释

1．基因表达：答案：基因表达是指储存遗传信息的基因经过转录和翻译而形成表型性状的过程。2．顺式作用元件：顺式调控元件是基因周围能与特异转录因子结合而影响转录的DNA序列。主要是起正性调控的顺式作用元件，包括启动子、增强子、静止子。

三、问答题

1.乳糖操纵子的调控方式