1.mRNA(信使RNA）MessengerRNAs-arethenucleicacidsthat"record"informationfromDNAinthecellnucleusandcarryittotheribosomesandareknownasmessengerRNAs(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）TranslationistheprocessbywhichthegeneticmessagescarriedbymRNAaredecodedandusedtobuildproteinsinthecytoplasm1.Stationcytoplasm2.TempletmRNA3.Materialaminoacids4.ProductsproteinsAsetofthreenucleotidebasesonanmRNAmoleculeiscalledacodon.UCAUGAUUAmRNACODONCODONCODON.(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GUG4.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）UCAUGAUUAAUCMetUUATypAsetofthreenucleotidebasesonatRNAmoleculeiscalledananticodon(反密码）AAULeucineDNARNAPROTEINTranscriptionTranslationReplication中心法则小结http://www.johnkyrk.com/DNAanatomy.htmlDNAbases=RNAbase=3aminoacidQuestions1.FortheDNAstrand5'-TACGATCATAT-3'thecorrectcomplementaryDNAstrandis:A.3'-TACGATCATAT-5‘B.3'-ATGCTAGTATA-5'C.3'-AUGCUAGUAUA-5‘D.3'-GCATATACGCG-5'E.3'-TATACTAGCAT-5'2.IntheMeselson-StahlDNAreplicationexperiment,ifthecellswerefirstgrownformanygenerationsinN-15containingmedia,andthenswitchedtoN-14containingmedia,whatpercentoftheDNAhad1lightstrandand1heavystrandafter2generationsofgrowthinN-14growthmedia?A.0B.25C.50D.75E.100BC3.ThreetypesofRNAinvolvedincomprisingthestructuralandfunctionalcoreforproteinsynthesis,servingasatemplate(模板)fortranslation,andtransportingaminoacid,respectively,are:AmRNA,tRNA,rRNABrRNA,tRNA,mRNACtRNA,mRNA,rRNADtRNA,rRNA,mRNAErRNA,mRNA,tRNA4.AmessengerRNAis336nucleicacids,includingtheinitiatorandterminationcodons.ThenumberofaminoacidsintheproteintranslatedfromthismRNAis:A999B630C330D111E1105.WithwhatmRNAcodonwouldthetRNAinthediagrambeabletoformacodon-anticodonbasepairinginteraction?A.3'-AUG-5‘B.3'-GUA-5‘C.3'-CAU-5‘D.3'-UAC-5‘E.3'-UAG-5'EDA
