雨课堂学堂在线学堂云《Molecular Biology（中国医科）》单元测试考核答案

第1题Theexperimentof15NlabeledDNAwascarriedoutbyMeselsonandStahlin1958thatfirstproves()AthatDNAcanbereplicated.BthatDNAgenecantransfertomRNA.CthatDNAgenecanexpressprotein.DthemechanismofDNAsemiconservativereplication.EthemechanismofDNAconservativereplication.第2题WhichoneiscorrectaboutOkazakifragments?()AThereareOkazakifragmentsineachnewstrandsofDNABTheOkazakifragmentsarelongerinprokaryotesthanineukaryotesCThegenerationofOkazakifragmentsdonotrequireRNAprimer.DOkazakifragmentsareproducedbyDNApol

IEOkazakifragmentsaretheRNAsegmentscatalyzedbyprimase.第3题ThegenerationofOkazakifragmentsisbecause()AeukaryoteshavemultipleinitiationsitesofDNAreplication.BthevelocityofDNAreplicationistoofast.CthesynthesisofRNAprimersisinsufficient.Dthedirectionofthereplicationoflaggingstrandsisoppositetothatofunwinding.EthelackofDNAligase.第4题IntheprocessofDNAreplication,thenewstrandisthat()Athedirectionofonestrandis5′→3′,theotheris3′→5′.Bthedirectionofthetwostrandsis3′→5′.Cthedirectionofthetwostrandsis5′→3′.Dbothstrandsaresynthesizedinacontinuousfashion.Ebothstrandsaresynthesizedinadiscontinuousfashion.第1题WhichoneiscorrectaboutprokaryoticDNA-pol?()ADNA-polIIIisthepolymerasethathasthelargestamountincell.BDNA-polIIIhas5´→3´polymerizingactivityand3´→5´exonucleaseactivity.CAllarefatalaftergenemutation.DDNA-polIistheprimarypolymerase.EDNA-polIIIhasthefunctionofremovingprimer.第2题WhichoneiscorrectabouteukaryoticDNA-pol?(

)ADNA-polδissimilarwithDNA-pol

IBDNA-polγhasthefunctionofrepairduringreplication

CDNA-polεistheprimarycatalyzedenzymeintheelongationofreplication

DDNA-polβistheenzymeofmitochondrialDNAsynthesis

EDNA-polαhastheprimaseactivity

正确答案：E第3题AboutE.coliDNApolymeraseⅠ,thecorrectdepictionisthat(

)Aithasnoexonucleaseactivity.Bithasendonucleaseactivity.CitistheprimaryenzymeinvolvedinE.coliDNAreplicationDithasarealtimeproofreadingfunctionEtheshortersegmentwhichderivefromhydrolysisofDNApolymeraseⅠiscalledKlenowfragment.Problems：EnzymesandproteinfactorsrequiredinDNAreplication第1题Whichenzymecannotcatalyzetheformationofphosphodiesterlinkage?()ADNA-polIIIBDNA-polICDNAligaseDtopoisomeraseEhelicase正确答案：E第2题ThefunctionofDNAtopoisomeraseis()AtounwindDNAdoublehelix.BtorelievethesupercoilingduringDNAunwinding.Ctohydrolyzeprimers,prolongandlinkDNAsegments.DtoidentifytheoriginsiteofDNAreplication.Etostabilizetheunwindhelix.第3题ThefunctionofDNAligaseis()AtorelievetorsionalstraingeneratedbyDNAunwinding.BtosynthesizeRNAprimer.CtoformDNAsuperhelix.DtocatalyzethejoiningoftheendsoftwofragmentsofDNA.Etoremoveprimersandfillingaps.第4题Whichoneiswrongaboutprimase?

(

)AItcancatalyzethesynthesisofRNAprimers.BThematerialisNTP.CThetemplateisonepartofunwindingDNA.DThestartingofprimaserequiresdnaB.EThesynthesisofRNAprimeris3′→5′.正确答案：EProblems：DNAreplicationinprokaryotes第1题ThefunctionofRNAprimerintheprocessofreplicationis()AtoactivateDNA-polIII.BtoundothedoublestrandDNA.Ctooffer5′terminalendswhichactasthebeginningofnewDNA.Dtooffer3′terminalendswhichactasthebeginningofnewDNA.Etooffer3′terminalactasthebeginningofnewRNA.第2题WhichenzymehasnouseforDNAreplication?()ADNA-dependentDNApolymeraseBDNA-dependentRNApolymeraseCDNAligaseDtopoisomeraseErestrictionendonuclease正确答案：E第3题Theproductofreplicationis5′-GCTAGAT-3′,thenthetemplateis()A5′-GCTAGAT-3′.B5′-CGATCTA3′C3′-CGATCTA-5′D3′-GCTAGAT-5′E5′-CGAUCUA-3′Problems：DNAreplicationineukaryotes第1题Whichoneisnotcorrectabouttelomerase?()ATelomerasehastheactivityofreversetranscriptase.BTelomeraseisthepolymerofDNAandprotein.CThefunctionoftelomeraseistokeeptheintegrityofeukaryoticDNA.DThedeclineoftelomeraseactivityisrelatedtocellaging.EThecatalyticmechanismoftelomeraseisdescribedasinchwormmodel.Problems：DNAReplication-6ReverseTranscription第1题Reversetranscriptionis()AtheDNAbiosynthesisusingRNAastemplate.BtheRNAbiosynthesisusingDNAastemplate.CtheproteinbiosynthesisusingRNAastemplate.DtheprocessofproteinusingDNAastemplateDNAEtheprocessofRNAusingproteinastemplate.Problems：DNATemplateandPromoterinTranscription第1题ThesequenceofsensestrandonDNAis5′GTCAACTAG3′,thetranscriptionproductsis()A5′-TGATCAGTC-3′.B5′-CUAGUUGAC-3′.C5′-CAGUUGAUC-3′.D5′-CTGACTAGT-3′.E5′-GACCUAGUU-3′.第2题Whichiscorrectoneaboutasymmetrictranscription?()Atranscriptionafterbidirectionalreplication.Btranscriptiononthesametemplatestrandappearsboth5′→3′and3′→5′directions.Ctemplatestrandisn’talwaysonthesameDNAstrand.Daftertranscriptionandtranslation,thepolypeptideincludesasymmetric“C”atom.Etranscriptionwithoutregularpattern.第3题Transcriptionandreplicationhavesomesimilarities,butexceptthat()ADNAistemplatestrandBthebondbetweenthetwonucleotides.CtheenzymesarebothDNA-dependent.Dtwocomplementarystrandsaresynthesizedatthesametime.Eobeythebasecouplingrules.Problems：RNAPolymerase第1题Whichonecanrecognizethepromoter?()AαsubunitofRNApolymeraseBβsubunitofRNApolymeraseCβ′subunitofRNApolymeraseDσsubunitofRNApolymeraseEdnaBprotein第2题Ineukaryotes,thetranscriptionproductsofRNApolymeraseⅡis()AhnRNA.B18SrRNA.C28SrRNA.DtRNA.EalloftheRNA.第3题WhichenzymecancatalyzethetranscriptionoftRNAand5SrRNA?(

)ARNApolymeraseⅠBreversetranscriptaseCRNApolymeraseDRNApolymeraseholoenzymeERNApolymeraseⅢ正确答案：E第4题RifampicinisthespecificinhibitorofRNApolymerase,thebindingsiteis()Aβsubunit.Bαsubunit.Cβ′subunit.Dσsubunit.Eωsubunit.第5题45S-rRNAis()ArRNAofbigsubunitofribosome.BrRNAofsmallsubunitofribosome.Cpre-RNAofrRNAexceptfor5SRNA.Dpre-RNAofrRNAexceptfor5.8SRNA.Econsistsofdifferenttranscriptionproducts.Problems：ProkaryoticTranscription第1题Thefunctionofρfactoris()Atobindwithinhibitoronpromoter.BtoincreasethevelocityofRNAsynthesis.CtoreleaseRNApolymerasefrompromoter.Drelatedtotheterminationoftranscription.Etopermitinitiationofspecifictranscription.第2题ThePribnowboxofprokaryoteis()AtheinitiationsiteoftranscriptionBtheinitiationsiteoftranslationCthesitewhereRNApolymeraseandDNAtemplatestrandcanbindstably.DtheactivecenterofDNApolymeraseEtheinitiationsiteofDNAsynthesis第3题Intheelongation,thebindingbetweenRNApolymeraseandDNAtemplatestrand:()AholoenzymebindswiththetemplatestrandBlooselybindingwhichmakesmovementeasily.Cfirmlybinding.Dcoreenzymecanbindtothespecificsiteoftemplatestrand.Esameasthestateofinitiation.Problems：EukaryoticTranscription第1题Transcriptionfactoris()Acomponentsofpolymeraseinprokaryotes.Bcomponentsofpolymeraseineukaryotes.Cincludesα,β,γsubunits.Dtrans-actingfactoringeneexpressionregulation.Epromotoroftheeukaryotictranscription.第2题Pre-initiationcomplex()ofeukaryotesis()ARNApolymeraseandTATAATsequences.BRNApolymerasebindtoTATAsequences.CthetranscriptionfactorsinteractwitheachotherandbindwithRNApolymeraseandDNAtemplatestrand.DαfactorbindwithRNApolymerase.Erepressordissociatesfromoperoncomplexafterallosterism.正确答案：CC第3题Thetranscriptionfactors(TFI,TFII,TFIII)arenamedaccordingto()AincludingI,II,IIIsubunits.BRNApolymeraseI,II,IIIineukaryotes.CthetranscriptedgenesareI,II,III.DactiononGC,CAAT,TATAsequencesrespectively.Eactionontherepressorgene,-35regionand-10region.Problems：RNAProcessing第1题hnRNAsplicingineukaryotesdependson()AsnRNA.Brestrictionendonuclease.Cribozyme.Dprotease.ERNase.第2题Exonis()ADNAsequenceswhichdon’ttranscriptBmutationofgeneCnoncodingregionoftheeukaryoticstructuregene.Dcodingregionoftheeukaryoticstructuregene.EsplitDNAfragments.第3题Thepost-transcriptionalprocessingofhnRNAincludesthelistedthingsexceptfor(

)Acappingat5′-end.Btailingat3′-endwithpolyACmethylationDphosphorylationEspliceintronsandligateexonsProblems：Geneticcodon第1题Thereadingdirectionofgeneticcodonis()Anodirections.B3′→5′.C5′→3′.DNterminus→Cterminus.ECterminus→Nterminus.第2题Whichcodonisboththeinitiationcodonandthecodonformethionine?()ACUUBACGCCAGDAUGEUCG第3题Whichpropertyofgeneticcodoniscorrelatedtoframeshiftmutation?()AcommalessBdegeneracyCwobbleDuniversalEAlloftheaboveisnotcorrect.Problems：Systemofproteinsynthesis第1题Whichiscorrectaboutproteinbiosynthesis?()ADirectionis3′endto5′endonmRNA.BDirectionisNterminustoCterminus.CDirectionisCterminustoNterminus.DDirectedby28SrRNA.EDirectedby4SrRNA.第2题Inmammaliancells,theproteinbiosynthesisislocatedon()Anucleus.BGolgiosome.Cnucleole.Dribosome.Elysosome.第3题ThefunctionoftRNAinproteinbiosynthesisis()Atobindanaminoacidtoanotheraminoacid.BtotransferaminoacidstothecertainsiteofmRNA.Ctoincreasethevalidconcentrationofaminoacids.DtolinkmRNAtoribosome.Etohavethefunctionofaminoacyl-tRNAsynthetase.Problems：Activationofaminoacids第1题Howmanyhighenergyphosphatebondsareusedineachaminoacidactivation?()A1B2C3D4E5第2题WhichistheformylgroupdonorofN-formylmethionine?()AN5,N10-CH2-FH4BN10-CH=NH-FH4CCODN10-CHO-FH4EN5,N10=CH-FH4第3题Aminoacyl-tRNAsynthetase()Aexistsinnucleus.Bhasspecificityonlytoaminoacidsrecognizable.ChasspecificityonlytotRNA.DhasspecificitytobothaminoacidsandtRNA.EneedsGTPforcatalyzingreaction.Problems：InitiationofProteinSynthesis第1题WhichoneisnotcorrectaboutprokaryoticS-DsequenceofmRNA?()AAGGAisthecoresequence.BTheonewhodiscoveredS-DsequenceisShine-Dalgarno.CIt’scomplementarysequencewith3′endof16S-rRNA.DItneedeIF.EItisalsocalledbindingsiteofribosome.第2题Thecorrectoneabouteukaryoticproteinbiosynthesisis()A70Sribosomeentertheribosomecyclefirst.B70Sribosomecan’tenterribosomecycle.C50Ssubunitentertheribosomecyclefirst.D60Ssubunitentertheribosomecyclefirst.E80Sribosomeenterribosomecycleafteritsdissociation.第3题FormationoftheribosomalinitiationcomplexforbacterialproteinsynthesisdoesNOTrequire:()AEF-Tu.BformylmethionyltRNAfMet.CGTP.Dinitiationfactor2(IF-2).EmRNA.Problems：ElongationofProteinSynthesis第1题Thecorrectoneaboutpeptidyltransferaseis()Atheproteinonthesmallsubunitofribosome.Btocatalyzetheformationofpeptidebonds.Ctoactintranslocationprocess.DitneedATPincatalyzing.EitneedGTPincatalyzing.第2题ThefunctionofEF-Tuis()Asynthesisofaminoacyl-tRNA.Btoaccelerateaminoacyl-tRNAenteringAsiteanddegradingGTP.Ctoregulatepeptidebondformation.Dactivityoftranslocase.EacceleratethereleasingoftRNA.第3题InbacteriatheelongationstageofproteinsynthesisdoesNOTinvolve:（）Aaminoacyl-tRNAs.BEF-Tu.CGTP.DIF-2.Epeptidyltransferase.Problems：TerminationofProteinSynthesis第1题Theterminationsignalsare()AAAACCCGGG.BUAAUAGUGA.CUCAAUGAGU.DUUUUUCUUG.ECCACCGCCU.第2题Inproteinbiosynthesis,thenumberofhighphosphatebondsconsumedforonepeptidebondformationis()A5B2C3D1E4正确答案：E第3题Polysomemeansmany()Aribosomes.BribosomesbindtoonemRNAandsynthesizepolypeptides.Csmallsubunitsofribosome.Dbigsubunitsofribosome.Esmallsubunitsofribosomewithaminoacyl-tRNA.Problems：Posttranslationalprocessing第1题Thepost-translationprocessingdoesNOTinclude()AsubunitpolymerizationBmodificationofNterminusofpeptideCcovalentmodificationofsomeaminoacidsDsecretaryproteintargetingEproteindenaturation正确答案：EProblems：IntroductionandProkaryoticDNA-BindingProteins第1题Whatisthegenome?AThecompletesetofgeneticmaterialofanorganismBThesetofgenesthatareexpressedinaspecifictissueCThesetofproteinsthatareinvolvedinDNAreplicationDThesetofenzymesthatareinvolvedinproteinsynthesis第2题Whichofthefollowingisanexampleofaconstitutivegene?AGenesinvolvedincelldifferentiationBGenesinvolvedinresponsetostressCGenesinvolvedinbasiccellularfunctionssuchasmetabolismDGenesinvolvedinimmuneresponse第3题Whatisthemainfunctionofhousekeepinggenes?A

ToregulategeneexpressionBTorespondtoenvironmentalstressCTomaintainbasiccellularfunctionsDTocontrolcelldifferentiation第4题Whatisinductioningeneexpression?ATheprocessbywhichgenesareturnedoffinresponsetoastimulusBTheprocessbywhichgenesareturnedoninresponsetoastimulusCTheprocessbywhichgenesaremutatedDTheprocessbywhichgenesaredeleted第5题RegulatedExpressionofGenesisRequiredfor?ADevelopmentBDifferentiationCAdaptationDAlloftheaboveProblems：Lacoperon第1题WhatdoyoupredictwouldhappenifyoureplacetheLacoperator

DNAfromtheLacoperonwiththeDNAfromtheoperatorregionfromthetryptophanoperon?AThepresenceoflactosewillnotcauseallostericchangestotheLacrepressorBTheLacoperonwillnotbetranscribedwhentryptophanlevelsarehighCThelackofglucosewillnolongerallowCAPbindingtotheDNADRNApolymerasewillonlybindtotheLacpromoterwhenlactoseispresent第2题Thelacoperonconsistsof:AApromoter,anoperator,andthreestructuralgenesBApromoter,anoperator,andonestructuralgeneCApromoterandthreestructuralgenesDAnoperatorandthreestructuralgenes第3题Therepressorproteinforthelacoperonbindsto:AThepromoterregionBTheoperatorregionCThestructuralgenesDTheregulatorygenes第4题Thelacoperonisanexampleof:APositiveregulationBNegativeregulationCBothpositiveandnegativeregulationDNoregulation第5题Thetworegulatoryproteinsthatcontrolthelacoperonare:ACAPandRNApolymeraseBCAPandLacZCLacIandLacZDLacIandCAPProblems：Theλrepressor第1题Thelysogenicpathwayisaprocessbywhich:ABacteriareplicatetheirDNABBacteriaundergocelldivisionCViralDNAintegratesintothehostcell'sgenomeDViralDNAreplicatesindependentlyofthehostcell'sgenome第2题Theλrepressorisinvolvedintheregulationofthe:ALyticpathwayBLysogenicpathwayCBoththelyticandlysogenicpathwaysDNeitherthelyticnorlysogenicpathways第3题TheCroproteinbindstoaspecificDNAsequenceknownasthe:AOperator1(OR1)BOperator2(OR2)CPromoterDEnhancer第4题TheCroproteinisanexampleofa:ARegulatoryproteinBStructuralproteinCEnzymeDLipid第5题Thelyticpathwayischaracterizedby:AThereleaseofviralparticlesfromthehostcellBThemaintenanceofastablerelationshipbetweenthevirusandthehostcellCThereplicationoftheviruswithinthehostcellDTheintegrationofviralDNAintothehostcell'sgenomeProblems：Tryptophanoperon第1题TheTryptophanoperonisasystemofgenesinvolvedinthebiosynthesisoftheaminoacidtryptophan.Itisfoundin:ABacteriaBFungiCPlantsDAnimals第2题TheTryptophanoperonisanexampleofa(n):AInducibleoperonBRepressibleoperonCConstitutiveoperonDTranscriptionfactor第3题Whatisattenuation?ATheincreaseinsignalstrengthasittravelsthroughamediumBThedecreaseinsignalstrengthasittravelsthroughamediumCThereflectionofasignaloffofasurfaceDTheabsorptionofasignalbyareceiver第4题Attenuationisaregulatorymechanismthatcontrolsgeneexpressionatthelevelof:ADNAreplicationBTranscriptionCTranslationDPost-translationalmodification第5题ThefollowingstatementabouttryptophanoperonregulationiscorrectAInthepresenceoftryptophan,onlytheprecursormRNAisproducedBWhenleuco-aminoacid,transcriptionalinhibitionCIstheregulationoftranslationlevelDHasananti-terminationeffectEWhentryptophanispresent,itissuppressedProblems：EukaryoticCis-actingelements第1题1.

Whichofthefollowingisakeydifferencebetweentranscriptioninprokaryotesandeukaryotes?AEukaryotictranscriptionoccursinthenucleus,whileprokaryotictranscriptionoccursinthecytoplasmBEukaryotictranscriptionrequirestheuseofmultipleRNApolymerases,whileprokaryotictranscriptiononlyusesoneCEukaryotictranscriptioninvolvestheprocessingofpre-mRNA,whileprokaryotictranscriptiondoesnotDEukaryotictranscriptionrequirestheuseofaprimer,whileprokaryotictranscriptiondoesnot第2题Whatarecis-actingelements?ADNAsequencesthatregulatetheexpressionofgenesonthesamechromosomeBProteinsthatbindtoDNAandregulategeneexpressionCRNAmoleculesthatinteractwithotherRNAstoregulategeneexpressionDDNAsequencesthatregulatetheexpressionofgenesondifferentchromosomes第3题Whichofthefollowingisnotatypeofcis-actingelement?AEnhancerBSilencerCPromoterDTranscriptionfactor第4题Whichofthefollowingisnotacomponentofapromoter?ATATAboxBEnhancerCCAATboxDGCbox第5题WhichenzymerecognizestheTATAbox?ARNApolymeraseIBRNApolymeraseIICRNApolymeraseIIIDDNApolymeraseProblems：EukaryoticTranscriptionFactors第1题WhichofthefollowingisNOTafunctionoftranscriptionfactors?ABindingtoenhancersorpromoterstoactivateorrepressgeneexpressionBRecruitingRNApolymerasetoinitiatetranscriptionCSplicingRNAtoremoveintronsDModifyingchromatinstructuretomakegenesmoreorlessaccessibletotranscriptionmachinery第2题Homeodomainproteinsarecharacterizedby:AAhelix-turn-helixmotifBAzincfingermotifCAleucinezippermotifDAbeta-sheetmotif第3题Thezinc-fingerdomaincontains:AAzincionthatmediatesprotein-DNAinteractionsBAhelix-turn-helixmotifthatbindstoDNACBothaandbDNeitheranorb第4题Nuclearhormonereceptorsareactivatedby:ALipidsBProteinsCCarbohydratesDNucleicacids第5题Theligand-bindingdomainofanuclearhormonereceptorislocated:AInsidethenucleusBInthecytoplasmCInthecellmembraneDIntheGolgiapparatusProblems：ChromatinRemodeling第1题Howmanytypesofhistonesarethereinanucleosome?AOneBTwoCThreeDFour第2题Whatistheeffectofhistoneacetylationonchromatinstructure?AItloosensthestructureofchromatinBIttightensthestructureofchromatinCIthasnoeffectonchromatinstructureDItdegradesthehistoneproteins第3题WhatisthedifferencebetweenHATsandHDACs?AHATsaddacetylgroupstohistones,whileHDACsremovethemBHATsaddmethylgroupstohistones,whileHDACsremovethemC

HATsaddphosphategroupstohistones,whileHDACsremovethemDHATsaddubiquitingroupstohistones,whileHDACsremovethem第4题WhereintheDNAmoleculedoescytosinemethylationoccur?AInthesugarphosphatebackboneoftheDNAmoleculeBInthenitrogenousbasesoftheDNAmoleculeCInthehistoneproteinsassociatedwiththeDNAmoleculeDInthephosphategroupsattachedtothehistoneproteinsProblems：IntroductionANDPrimarymessenger第1题The“ligand”presentsinthereceptor-ligandcomplexesinthissectionisreferredto()ALipidmoleculesincellmembranesBProteinmoleculesincellmembranesCprimarymessengerDsecondarymessenger第2题Extracellularsignalmoleculesarealsoknownas()AprimarymessengerBsecondarymessengerCthirdmessengerDnoneoftheabove第3题WhichofthefollowingisNOTacharacteristicofaprimarymessenger?AItbindstoareceptoronthecellsurfaceBItactivatesasignalingpathwayCItisusuallyaproteinorpeptideDItisproducedbythetargetcell第4题Whichofthefollowingisafunctionofareceptor?AToproduceaprimarymessengerBTotransmitasignalacrossasynapseCTobindtoaligandandinitiatearesponseDToregulategeneexpression第5题Whichofthefollowingistrueaboutparacrinesignaling?AItrequiresdirectcontactbetweencellsBItinvolvesthereleaseofsignalingmoleculesintothebloodstreamCItisslowerthanendocrinesignalingDItisfasterthanendocrinesignalingProblems：SecondMessengers第1题Whichoneofthefollowingisnotasecondmessenger?AcGMPBIP3CDAGDmRNA第2题Whichofthefollowingisafunctionofsecondmessengersinsignaltransduction?AAmplifythesignalBInitiategeneexpressionCActivateionchannelsDAlloftheabove第3题WhatistheroleofaGproteininthesecondmessengersignalingpathway?AItdirectlyactivatesenzymesinthecellBItbindstoandactivatesadenylatecyclaseCItbindstoandactivatesionchannelsDItamplifiesthesignalbyactivatingmultiplesecondmessengermolecules第4题WhichofthefollowingisanexampleofasecondmessengermoleculethatactivatesproteinkinaseA(PKA)?AcAMPBCalciumionsCGTPDAdenylatecyclase第5题WhatistheroleofaGs-coupledreceptor?AToactivateadenylatecyclaseandincreasecAMPlevelsBToactivateproteinkinaseA(PKA)CToactivatephospholipaseC(PLC)DToactivateionchannelsProblems：Gproteins第1题WhichofthefollowingisNOTatypeofGprotein?AGsBGiCGqDGr第2题WhenaGproteinisactivated,it:ABindsdirectlytoaneffectorproteinBReleasesGDPandbindsGTPCUndergoesphosphorylationbyakinaseDCleavesamembranelipidtoreleaseasecondmessenger第3题WhatisthemechanismofGproteinactivation?AThealphasubunitbindstoGTPanddissociatesfromthebetaandgammasubunits,activatingdownstreameffectorsBThealphasubunitbindstoGDPanddissociatesfromthebetaandgammasubunits,inhibitingdownstreameffectorsCThebetaandgammasubunitsbindtoGTPandactivatedownstreameffectorsDThebetaandgammasubunitsbindtoGDPandinhibitdownstreameffectors第4题WhichproteinfamilydoesRasbelongto?AGprotein-coupledreceptorsBTyrosinekinasesCSmallGTPasesDTranscriptionfactors第5题HowdosmallG-proteinsdifferfromGproteins?ASmallG-proteinsaresmallerinsizeBSmallG-proteinsarealwaysactiveCSmallG-proteinsarenotcoupledtoreceptorsDSmallG-proteinsareonlyfoundineukaryoticcellsProblems：Receptors第1题Whatistheroleofreceptorsinsignaltransduction?AReceptorsconvertextracellularsignalsintointracellularsignalsBReceptorsbindtoligandsandtransportthemacrossthecellmembraneCReceptorscatalyzechemicalreactionstoproduceintracellularsignalsDReceptorsregulategeneexpressioninresponsetoextracellularsignals第2题WhichofthefollowingisNOTafunctionofreceptors?ASensingenvironmentalstimuliBRegulatinggeneexpressionCTransmittingsignalsacrosscellsDCatalyzingchemicalreactions第3题WhichofthefollowingisnotacomponentoftheMAPKpathway?AMAPkinasekinasekinase(MAPKKK)BMAPkinasekinase(MAPKK)CMAPkinase(MAPK)DGprotein第4题Whatisthefunctionofionchannelreceptors?AToactivatesecondmessengerpathwaysBTobindtoligandsandactivateGproteinsCTotransportionsacrossthecellmembraneDToactivateenzymeactivity第5题Whichofthefollowingisnotasurfacereceptor?AIonchannelsreceptorBGProtein-CoupledReceptorCEnzyme-CoupledReceptorDRetinoicacid

receptorProblems：cAMP-PKApathway第1题WhatisthefirststepinthecAMP-PKApathway?AActivationofadenylylcyclaseBActivationofproteinkinaseACActivationofphosphodiesteraseDActivationofGprotein-coupledreceptors第2题WhatisthesecondmessengerinthecAMP-PKApathway?AGproteinBProteinkinaseACcAMPDAdenylylcyclase第3题WhatdoesCREBstandfor?ACyclicresponseelementbindingproteinBCyclicribosomalelementbindingproteinCCyclicregulatoryelementbindingproteinDCyclicAMPresponseelementbindingprotein第4题WhatisthestructureofCRE?AAproteinBAlipidCAcarbohydrateDADNAsequence第5题ThereceptorcoupledwithGproteinis?ACyclicreceptorBSeven-transmembranereceptorCIntracellularreceptorDNuclearreceptorECytoplasmicreceptorProblems：Insulinsignalpathway第1题Whatisthefunctionofaproteinphosphatase?AToaddphosphategroupstoproteinsBToremovephosphategroupsfromproteinsCToactivateenzymesDTodeactivateenzymes第2题Whatistheprimarystructureofinsulin?AAsinglepolypeptidechainBTwopolypeptidechainslinkedbydisulfidebondsCThreepolypeptidechainslinkedbydisulfidebondsDFourpolypeptidechainslinkedbydisulfidebonds第3题Whichofthefollowingisthecorrectorderofeventsininsulinreceptoractivation?AInsulinbinding→receptordimerization→autophosphorylation→insulinreceptorsubstrateactivationBReceptordimerization→autophosphorylation→insulinbinding→insulinreceptorsubstrateactivationCAutophosphorylation→insulinbinding→receptordimerization→insulinreceptorsubstrateactivationDInsulinbinding→autophosphorylation→receptordimerization→insulinreceptorsubstrateactivation第4题Whatisthenameofthedownstreamsignalingpathwaythatisactivatedbyinsulinreceptorsubstrate?API3K/AktpathwayBMAPK/ERKpathwayCJAK/STATpathwayDNF-κBpathway第5题Whatisasignalcascade?AAsequenceofchemicalreactionstriggeredbyasignalmoleculethatamplifiesandtransmitsthesignalwithinacellBAsequenceofphysicalinteractionsbetweenareceptorandaligandthatleadstoacellularresponseCAsequenceofgeneticmutationsthatresultinabnormalcellgrowthanddivisionDAsequenceofenzymaticreactionsthatbreakdownasignalmoleculeintoitscomponentpartsProblems：EGFsignalpathway第1题WhatisEGF?AAproteinkinaseBAsecondmessengerCAgrowthfactorDAtranscriptionfactor第2题HowdoesGrb2activateRas?ABydirectlybindingtoRasBByrecruitingtheSOSproteintotheplasmamembraneCByphosphorylatingRasDBydegradingRas第3题WhichdomainofGrb2isresponsibleforbindingtotheepidermalgrowthfactorreceptor(EGFR)?AS