10 Генетическая инженерия (1160079), страница 10
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See also fermentation.aldose: A simple sugar in which the carbonyl carbon atom is an aldehyde; that is,the carbonyl carbon is at one end of thecarbon chain.alkaloids: Nitrogen-containing organiccompounds of plant origin; often basic,and having intense biological activity.alkalosis: A metabolic condition in whichthe capacity of the body to buffer OH~ isdiminished; usually accompanied by anincrease in blood pH.allosteric enzyme: A regulatory enzyme,with catalytic activity modulated by thenoncovalent binding of a specific metabolite at a site other than the active site.allosteric site: The specific site on thesurface of an allosteric enzyme moleculeto which the modulator or effector molecule is bound.a helix: A helical conformation of a polypeptide chain, usually right-handed, withmaximal intrachain hydrogen bonding;one of the most common secondary structures in proteins.Ames test: A simple bacterial test forcarcinogens, based on the assumption thatcarcinogens are mutagens.amino acid activation: ATP-dependentenzymatic esterification of the carboxylgroup of an amino acid to the 3'-hydroxylgroup of its corresponding tRNA.amino acids: a-Amino-substituted carboxylic acids, the building blocks of proteins.amino-terminal residue: The onlyamino acid residue in a polypeptide chainwith a free a-amino group; defines theamino terminus of the polypeptide.aminoacyl-tRNA: An aminoacyl ester ofa tRNA.aminoacyl-tRNA synthetases: Enzymesthat catalyze synthesis of an aminoacyltRNA at the expense of ATP energy.aminotransferases: Enzymes that catalyze the transfer of amino groups froma-amino to a-keto acids; also called transaminases.ammonotelic: Excreting excess nitrogenin the form of ammonia.amphibolic pathway: A metabolic pathway used in both catabolism and anabolism.G-lG-2Glossaryamphipathic: Containing boi-h polar andnonpoiar domains.amphoteric: Capable of donating andaccepting protons, thus able to serve asan add or a base.anabolism: The phase of intermediarymetabolism concerned with the energyrequiring biosynthesis of cell componentsfrom smaller precursors.anaerobe: An organism that lives without oxygen.
Obligate anaerobe? die whenexposed to oxygen.anaerobic: Occurring in the abspnc-3 ofair or oxygen.anaplerotic reaction: An enzyme catalyzed reaction that can /• flen'rh the supply of intermediates in the citnb acicScycle.angstrom (A): A unit of T-ngth (10 ^ cm)used to indicate molecul..-: dimer.sior.s.anhydride: The product, f the coiviensation of I vvo carboxyl or p sphp+c rr->unsin which the elements OJ ,vater au dominated to form a compouixi with V\c general structure R—X—O---Z—U. vvhereII•:oX is either carbon or pho ho u,c,.anion-exchange resin: A polymer, t resinwith fixed cationic group:s<id 11 hechromatographic separation oi'ank »is.anomers: Two stereoisc « i of a ^ ^ensugar that differ only in i^ie conf.
*v rationabout the carbonyl (anor ric) ^ .hotatom.antibiotic: One of many dilferen organiccompounds that are fonrv - and ,-:Hratedby various species of mic -Tgamr.ni? andplants, ore toxic to other -pecies. ::j^d presumabi> have a defensive fmictL \.antibody: A defense protuii syn ?•]•>»• sizedby the immune system o- vortebir\i os. Seealso ini niunoglobulin.anticodon: A specific sequence o f ' t r e enucleoti'ies in a tRNA. co.nplementaTy toa codon for an amino aci-. .in an vHNA.antigen: A molecule capable of enuiingthe synthesis of a specif; r.ntibod}- in vertebrates.antiparallel: Describing ' ?*o lin^?v polymers that are opposite i% polarity or orientation.antipor*1: Cotransport <>•• o - > «; •••$across a membrane in opposite directions.apoenzyme: The protein oortion cf anenzyme, exclusive of any organic or incrganic ^factors or prosthe^u grou*.., taatmight be required for cj'^lytic activity.apolipoorotein: The prc/Tin compof a ii?:o*jrotein.asymmetric «?*rbon atom: A carbonatom that is -jvalently bonded to four different groups • nd thus may exist in twodifferent tetrol-.idral configurations.phipathic lipid molecules, forming thebasic structure of biological membranes.The hydrocarbon tails face inward to forma continuous nonpoiar phase.ATP (adenoiine triphosphate): A ribonucieoside 5 -^phosphate functioningas a phosph?.
. group donor in the cellenergy cycle; rries chemical energy betwe?:"1 metab-'•'' pathways by serving as ashared interr .* diate coupling endergonicand exergonic :eactions.bile salts: Amphipathic steroid derivatives with detergent properties, participating in digestion and absorption of lipids.ATP synthaf e: An enzyme complex thatforms ATP frnn ADP and phosphate during oxidative r^hosphorylation in the innermitochondria- viembn ne or the bacterialplaLrna mem? ae, and during photophosphorylation i.r 'hloroplasts.ATPase: An *. .^yme that hydrolyzes ATPto yield ADP n d phosphate; usually coupled to some vivocess requiring energy.attenuator: / n RNA sequence involvedm regulating t>je expression of certaingen^r,; function••> as a transcription terminator.binding energy: The energy derivedfrom noncovalent interactions betweenenzyme and substrate or receptor andligand.biocytin: The conjugate amino acid residue arising from covalent attachment ofbiotin, through an amide linkage, to a Lysresidue.biomolecule: An organic compound normally present as an essential componentof living organisms.biopterin: An enzymatic cofactor derivedfrom pterin and involved in certain oxidation—reduction reactions.biosphere: All the living matter on or inthe earth, the seas, and the atmosphere.autocroph: i\n organism that can synthesize its own (c-r.plex molecules from verysimple carbond nit^gen sources, suchas c? hon di r •••''•? and 'mmoniabiotin: A vitamin; an enzymatic cofactorinvolved in carboxylation reactions.auxin.
A playbranch migration: Movement of thebranch point in branched DNA formedfrom two DNA molecules with identicalsequences. See also Holliday intermediate.growth hormone.a a y "*ophi; .atant ,auxotroph): Amula it orga:/ 1 defe< ive in tha synthesis of a giver; ' ' jmolecJe, which must,jre be L1 ^plied fo^ the organism'sAvot »dro's :•"".nber (•*/): The number ofmolei.ales in : ;^:ram molecular weight (ad, of any ; npound (6.02 x 1023).baclr. ^iutat:' n: A mi cation that causesa m;:,'ant ger^. ..o regaui its wild-type basesequence.bar' ~ioph^(phaf^): A virus capableof replicating in a bacterial cell.bas:-?i metab lie rate: The rate of oxygenconsumption hv an arimal's body at complete ~est, lor ^ after a meal.rbast pair: l ,o nucleoides in nucleic acidchains that a^vr paired by hydrogen bonding of their ba,=;es; for example, A with Tor U, and G -.with C.p conforma^'oji: An extended, zigzagarnngement o; a polypeptide chain; acommon seco '.clary structure in proteins.ft co-.viation* ' adati-'j degradation offatty acids irJ' icetyl-CoA by successiveoxidations iX l.v /3-Ccx\,on atom.bilayer: A douole la>er of oriented am-bond energy: The energy required tobreak a bond.buffer: A system capable of resistingchanges in pH, consisting of a conjugateacid-base pair in which the ratio of proton acceptor to proton donor is near unity.calorie: The amount of heat required toraise the temperature of 1.0 g of waterfrom 14.5 to 15.5 °C.
One calorie (cal)equals 4.18 joules (J).Calvin cycle: The cyclic pathway used byplants to fix carbon dioxide and producetriose phosphates.cAMP: See cyclic AMP.CAP: See catabolite gene activator protein.capsid: The protein coat of a virion orvirus particle.carbanion: A negatively charged carbonatom.carbocation: A positively charged carbonatom; also called a carbonium ion.carbon fixation reactions: In photosynthetic cells, the light-independent enzymatic reactions involved in the synthesisGlossaryof glucose from CO2, ATP, and NADPH;also known as the dark reactions.carboxyl-terminal residue: The onlyamino acid residue in a polypeptide chainwith a free a-carboxyl group; defines thecarboxyl terminus of the polypeptide.carotenoids: Lipid-soluble photosyntheticpigments made up of isoprene units.catabolism: The phase of intermediarymetabolism concerned with the energyyielding degradation of nutrient molecules.catabolite gene activator protein(CAP): A specific regulatory protein thatcontrols initiation of transcription of thegenes producing the enzymes required fora bacterial cell to use some other nutrientwhen glucose is lacking.catalytic site: See active site.catecholamines: Hormones, such as epinephrine, that are amino derivatives ofcatechol.cation-exchange resin: An insolublepolymer with fixed negative charges; usedin the chromatographic separation of cationic substances.cDNA: See complementary DNA.central dogma: The organizing principleof molecular biology: genetic informationflows from DNA to RNA to protein.centromere: A specialized site within achromosome, serving as the attachmentpoint for the mitotic or meiotic spindle.cerebroside: Sphingolipid containing onesugar residue as a head group.channeling: The direct transfer of a reaction product (common intermediate) fromthe active site of one enzyme to the activesite of a different enzyme catalyzing thenext step in a sequential pathway.chemiosmotic coupling: Coupling ofATP synthesis to electron transfer via anelectrochemical H+ gradient across amembrane.chemotaxis: A cell's sensing of andmovement toward, or away from, a specific chemical agent.chemotroph: An organism that obtainsenergy by metabolizing organic compounds derived from other organisms.chiral compound: A compound that contains an asymmetric center (chiral atomor chiral center) and thus can occur intwo nonsuperimposable mirror-imageforms (enantiomers).chlorophylls: A family of green pigmentsfunctioning as receptors of light energy inphotosynthesis; magnesium-porphyrincomplexes.chloroplasts: Chlorophyll-containing photosynthetic organelles in some eukaryoticcells.chromatin: A filamentous complex ofDNA, histones, and other proteins, constituting the eukaryotic chromosome.chromatography: A process in whichcomplex mixtures of molecules are separated by many repeated partitioningsbetween a flowing (mobile) phase and astationary phase.chromosome: A single large DNA molecule and its associated proteins, containing many genes; stores and transmits genetic information.chylomicron: A plasma lipoprotein consisting of a large droplet of triacylglycerols stabilized by a coat of protein andphospholipid; carries lipids from the intestine to the tissues.cis and trans isomers: See geometricisomers.cistron: A unit of DNA or RNA corresponding to one gene.citric acid cycle: A cyclic system of enzymatic reactions for the oxidation ofacetyl residues to carbon dioxide, in whichformation of citrate is the first step; alsoknown as the Krebs cycle or tricarboxylicacid cycle.clones: The descendants of a single cell.cloning: The production of large numbersof identical DNA molecules or cells from asingle ancestral DNA molecule or cell.closed system: A system that exchangesneither matter nor energy with the surroundings.
See also system.cobalamin: See coenzyme B12.codon: A sequence of three adjacent nucleotides in a nucleic acid that codes for aspecific amino acid.coenzyme: An organic cofactor requiredfor the action of certain enzymes; oftencontains a vitamin as a component.coenzyme A: A pantothenic acidcontaining coenzyme serving as an acylgroup carrier in certain enzymatic reactions.coenzyme B12: An enzymatic cofactorderived from the vitamin cobalamin, involved in certain types of carbon skeletalrearrangements.cofactor: An inorganic ion or a coenzymerequired for enzyme activity.cognate: Describing two biomoleculesthat normally interact; for example, anenzyme and its normal substrate, or areceptor and its normal ligand.cohesive ends: See sticky ends.G-3cointegrate: An intermediate in the migration of certain DNA transposons inwhich the donor DNA and target DNA arecovalently attached.colligative properties: Properties of solutions that depend on the number of solute particles per unit volume; for example, freezing-point depression.common intermediate: A chemical compound common to two chemical reactions,as a product of one and a reactant in theother.competitive inhibition: A type of enzyme inhibition reversed by increasing thesubstrate concentration; a competitiveinhibitor generally competes with the normal substrate or ligand for a protein'sbinding site.complementary: Having a molecularsurface with chemical groups arranged tointeract specifically with chemical groupson another molecule.complementary DNA (cDNA): A DNAused in DNA cloning, usually made byreverse transcriptase; complementary to agiven mRNA.configuration: The spatial arrangementof an organic molecule that is conferredby the presence of either (1) double bonds,about which there is no freedom of rotation, or (2) chiral centers, around whichsubstituent groups are arranged in a specific sequence.
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