胞生物学期中考试试题05答案

1细胞生物学期中试卷5一、填空题(每空0.5分，共5分)1.决定红细胞ABO血型的物质是糖脂，它由脂肪酸和寡糖素链组成。A型血糖脂上的寡糖链较O型多一个；B型血仅多一个。2.根据题意,将与A、B、C、D相对应的词用连线连起来:Cellscommunicateinwaysthatareanalogoustohumancommunication.Decidewhichofthefollowingformsofhumancommunicationareanalogoustoautocrine,paracrine,endocrine,andsynapticsignalingbycells.A.Atelephoneconversation:autocrineB.Talkingtopeopleatacocktailparty:endocrineC.Aradioannouncement:synapticsignalingD.Talkingtoyourself:paracrine3.Whatisthemajorfactorthatdeterminesthelimitofresolutionofalightmicroscope?4.编码载脂蛋白B的基因在肠组织中转录成mRNA后,第2153位的C被形成U,使CAA密码转变成终止密码UAA,使翻译提前终止。5.是细胞外基质的受体蛋白。在结构上，它们是异二聚体，。这种跨膜蛋白的细胞外部分有一个球形的头部，可与细胞外基质蛋白结合，而细胞质结构域则可与相结合。二、判断以下各题是否正确,若正确,用T表示,不正确用F表示,并做简要说明。(每题1分，共10分)1.BoththeGTP-boundsubunitsandnucleotide-freecomplexes,butnotGDP-bound,fullyassembledGproteins,activateothermoleculesdownstreamofG-protein-linkedreceptors.答:2.Thedensityofwaterislessthanthedensityofice.答:3.Waterhasahighspecificheat.答:4.Thereisnofundamentaldistinctionbetweensignalingmoleculesthatbindtocell-surfacereceptorsandthosethatbindtointracellularreceptors.答:5.Howisitthatdifferentcellscanrespondindifferentwaystoexactlythesamesignalingmoleculeevenwhentheyhaveidenticalreceptors?答:6.ProteinkinaseAitselfisdifferentindifferentcelltypes,whichexplainswhytheeffectsofcyclicAMPvarydependingonthetargetcell.答:7.Itisthoughtthatextracellularligandbindingtoareceptortyrosinekinaseactivatestheintracellularcatalyticdomainbypropagatingaconformationalchangeacrossthelipidbilayerthroughthesingletransmembranehelix.答:8.Atrialnatriureticpeptides(心钠肽)bindtoareceptorthatactivatesaGprotein,whichinturnactivatesguanylylcyclase(鸟苷环化酶)toproducecyclicGMPwhichthenactivatesacyclicGMP-dependentproteinkinase(PKG).答:9.Becauseprokaryoticcellshaveneithermitochondrianorchloroplasts,theycannotcarryouteitherATPsynthesisorphotosynthesis.答:210．电镜的波长与电压有关，电压越高，波长越短，分辨率越高。答:三、选择题(请将正确答案的代号填入括号，每题1分，共20分)1.Whichoneofthefollowingisincorrectforthebiogenesisofeukaryoticribosomes?()a.25-50%ofthepre-rRNAisdegradedb.Pre-rRNAbindstoribosomalproteinc.Pre-rRNAiscuttoformthreeclassesofrRNAd.Pre-rRNAismethylatede.TherRNAgeneforthe40Ssubunitistranscribedseparately2.The5SrRNAdiffersfromtheothercellularrRNAsinwhichofthefollowingways?()a.Thegenesarelocatedoutsidethenucleolus(核仁).b.ThegenesaretranscribedbyRNApolymeraseIII.c.Thepromoterregionofthe5SrRNAgeneisinternaltothegene.d.alloftheabove3．钙泵的作用主要是()。a．降低细胞质中Ca2+的浓度；b．提高细胞质中Ca2+的浓度；c．降低内质网中Ca2+的浓度；d．降低线粒体中Ca2+的浓度4.Plantguardcells(保卫细胞)haveahigher[C1-]thantheoutsideenvironment.Themostlikelyexplanationforthisis().a.Waterleavesthecellbyosmosis.b.C1-isdiffusingthroughtransmembranechannels.c.C1-diffusionisaidedbyamobilecarrier.d.AnactivetransportsymporttransportsC1-/H+.e.Noneoftheabove5.Thehormoneglucagons(胰高血糖素)stimulatesthebreakdownofstoredglycogeninliverandmusclecellsbythefollowingenzymes.Whichisthefirstenzymethatmustbeactivated?()a.ProteinkinaseAb.Phosphorylasekinasec.Glycogenphosphorylased.Proteinphosphatasee.Proteinphosphataseinhibitor-16.在下列组织中,紧密连接特别重要的有()a.Stomach(胃)andkidneysb.Smoothmusclec.Heartmuscled.Intestinalepithelialtissue(肠表皮组织)7.WhichoneofthefollowingwasusedtodeterminethestructureoftheDNAmolecule?()a.Transmission(透射)electronmicroscopeb.Scanningelectronmicroscopec.Differentialcentrifugatioin(差速离心)d.X-raycrystallography8.Aeukaryoticcellhas()a.Onecopyofeachribosomaltranscriptionunit.b.Thousandsofcopiesofthe5SrRNAgene.3c.TwocopiesofeachgeneforrRNAandribosomalproteins.d.TwocopiesofeachgeneforrRNAandonecopyofeachribosomalproteingene.9.AllofthefollowingaretrueaboutantisenseRNAexcept()a.IscomplementarytomRNA.b.Formsdouble-strandedRNA.c.Joinswiththe30Ssubunit.d.Inhibitsproteinsynthesis.10.Developingfrogembryostreatedwithanti-fibronectinantibodiesa.Developnormally.()b.Stopcelldivision.c.Haveabnormalcellmigration(迁移).d.Don'texhibitactionpotentials.11．肌动蛋白纤维对于黏着斑就像()对于半桥粒。a．肌球蛋白纤维b．角蛋白纤维c．微丝d．钙粘着蛋白12．配体(ligand)是（）。a．酶与底物共价结合的活性位点；b．酶与底物非共价结合的活性位点；c．对于一个与蛋白质以共价形式相作用的小分子的普遍称呼；d．对于一个与蛋白质以非共价形式相作用的小分子的普遍称呼；e．一个缺乏酶活性的球蛋白13．膜胆固醇的组成与质膜的性质、功能有着密切的关系,（）a．胆固醇可防止膜磷脂氧化；b．正常细胞恶变过程中，胆固醇/磷脂增加；c．胆固醇/磷脂下降，细胞电泳迁移率减少；d．在质膜相变温度以下，增加胆固醇，可以提高膜的流动性14．用抗纤连蛋白的抗体注射胚体，发现在神经系统发育过程中神经嵴细胞的迁移受到抑制。这些实验说明：()a．神经嵴发育包括抗体基因的表达；b．发育中的神经无需合成纤连蛋白；c．纤连蛋白/抗体复合物形成神经细胞的迁移途径；d．胚胎中的神经元在移动过程中必须与纤连蛋白暂时结合15．当胰岛素与其受体酪氨酸激酶结合后，随后发生的事件是()。a．IRS的结合→具有SH2区域的蛋白质的磷酸化→效应；b．与具有SH2区域的蛋白质结合→IRS的磷酸化→效应；c．自磷酸化并将IRS磷酸化→与具有SH2区域的蛋白质结合→效应；d．自磷酸化并与IRS结合→将具有SH2区域的蛋白质磷酸化→效应四、简答题(每题4分，共40分)1.WhatfunctionalrolesdotheECM(细胞外基质)andcellwallshareincommon?2.Discussthefollowinganalogy(相似):“Thedifferencesbetweentransportingaligandbyachanneloracarrierproteinarelikethedifferencesbetweencrossingariverbyabridgeoraferry(摆渡).3.EGTAchelates(螯合)Ca2+withhighaffinityandspecificity.Howwouldmicroinjection(微注射)ofEGTAaffectglucagon-triggeredbreakdownofglycogen(糖原)inliver?4.Thebasicstructureofbiologicalmembranesisdeterminedbythelipidbilayer,buttheirspecificfunctionsarecarriedoutlargelybyproteins.Explainyouranswer.45.Whydoesaredbloodcellmembraneneedproteins?6.Describethedifferentmethodsthatcellsusetorestrictprote