生物新人教版必修2 4.1《基因指导蛋白质的合成》

基因指导蛋白质的合成,1.mRNA(信使RNA）MessengerRNAs-arethenucleicacidsthatrecordinformationfromDNAinthecellnucleusandcarryittotheribosomesandareknownasmessengerRNAs(mRNA).（功能：作为编码蛋白质中氨基酸的模板）,2.rRNA(核糖体RNA）RibosomalRNAs-existoutsidethenucleusinthecytoplasmofacellinstructurescalledribosomesRibosomesaresmall,granularstructureswhereproteinsynthesistakesplace.Eachribosomeisacomplexconsistingofabout60%ribosomalRNA(rRNA)and40%protein.(功能：核糖体的组成结构的一部分）,3.tRNA(转运RNA）TransferRNAs-ThefunctionoftransferRNAs(tRNA)istodeliveraminoacidsonebyonetoproteinchainsgrowingatribosomes.（功能：转运氨基酸）,TranslationistheprocessbywhichthegeneticmessagescarriedbymRNAaredecodedandusedtobuildproteinsinthecytoplasm,1.Stationcytoplasm,2.TempletmRNA,3.Materialaminoacids,4.Productsproteins,AsetofthreenucleotidebasesonanmRNAmoleculeiscalledacodon.,.(翻译是在细胞质中进行的。它是指以信使RNA为模板，合成具有一定氨基酸顺序的蛋白质的过程。）,(场所；细胞质),(模板：信使RNA),(原料：氨基酸),(产物：蛋白质),(信使RNA上决定一个氨基酸的三个相邻的碱基叫一个密码子）,1.Eachcodonspecifiesasingleaminoacid.Forexample,CGCencodesarg.(一个密码子编码一个氨基酸，例如CGC编码精氨酸）,2.大多数氨基酸有多个密码子，例如，GUU，GUA都编码缬氨酸,3.AUG（编码甲硫氨酸）为起始密码子，翻译从此密码子开始，少数起始密码子为GUG,4.UAA,UAG,UGA（终止密码子，不编码任何氨基酸），翻译到次终止,1.InitiationAUG,GUG（起始密码子）,2.StopUAA,UAG,UGA（终止密码子）,3.Onecodondecidesoneaminoacid一个密码子决定一个氨基酸,4.oneaminoacidmayhavemanycodons一个氨基酸可有多个密码子,Proteinsynthesisoccursinthreestages:Initiation,ElongationandTermination.(蛋白质的合成包括三个步骤：起始，延长，终止),1.Initiation(起始)mRNAattachestotheribosome.(mRNA与核糖体结合）,AsetofthreenucleotidebasesonatRNAmoleculeiscalledananticodon(反密码）,DNAbases=RNAbase=3aminoacid,Questions,1.FortheDNAstrand5-TACGATCATAT-3thecorrectcomplementaryDNAstrandis:A.3-TACGATCATAT-5B.3-ATGCTAGTATA-5C.3-AUGCUAGUAUA-5D.3-GCATATACGCG-5E.3-TATACTAGCAT-5,2.IntheMeselson-StahlDNAreplicationexperiment,ifthecellswerefirstgrownformanygenerationsinN-15containingmedia,andthenswitchedtoN-14containingmedia,whatpercentoftheDNAhad1lightstrandand1heavystrandafter2generationsofgrowthinN-14growthmedia?A.0B.25C.50D.75E.100,B,C,3.ThreetypesofRNAinvolvedincomprisingthestructuralandfunctionalcoreforproteinsynthesis,servingasatemplate(模板)fortranslation,andtransportingaminoacid,respectively,are:AmRNA,tRNA,rRNABrRNA,tRNA,mRNACtRNA,mRNA,rRNADtRNA,rRNA,mRNAErRNA,mRNA,tRNA,4.AmessengerRNAis336nucleicacids,includingtheinitiatorandterminationcodons.ThenumberofaminoacidsintheproteintranslatedfromthismRNAis:A999B630C330D111E110,E,D,5.WithwhatmRNAcod