translation 翻译过程.ppt

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1、TranslationOncetheDNAcodehasbeenTranscribedontoamRNAmolecule,mRNAleavesthenucleusandmovesintothecytoplasm.InthecytoplasmthemRNAcombineswiththeRibosomestomakeEnzymes/Proteins.TheProcessofreadingthemRNAcodeandbuildinga(n)Enzyme/ProteiniscalledTranslation,orProteinSynthesis.InorderforTranslation/P

2、roteinSynthesistooccuracellneeds:1.mRNA(carryingtheDNAcode)2.Ribosomes3.AminoAcids4.tRNA(picksupaminoacidsinthecytosolandcarriesthemtotheribosomeswheretheywillbejoinedtogethertoformaProtein)ThemRNAismadeintheNucleusthroughtheprocessofTranscription.mRNAismadeupofRNAnucleotides.Eachgroupof3nucleo

3、tidesiscalledaCodonandcodesforoneaminoacidofthenewlyformingProtein.ThisSegmentofamRNAmoleculeis7codonslong,21nucleotides,andwillcodefor7aminoacidsRibosomes(theribosomesaretheactualsiteofTranslation/proteinsynthesis)MadeintheNucleolus,madeupofRibosomalRNA,rRNAAnimalsandPlantsgettheiraminoacidsth

4、esamewaytheygettheirNucleotides.TransferRNA(tRNA)tRNAisasmall,foldedRNAchain(74-93nucleotides)thatpicksupandtransfersspecificaminoacidstoagrowingpolypeptidechainattheribosomalsiteofproteinsynthesisduringtranslation.IthassitesforAminoAcidattachmentandanAnticodon.TheAnticodoniscomposedofcomplemen

5、tarybases.EachtRNAmoleculebindstoonlyonetypeofaminoacid.MorethanonetRNAexistsforeachaminoacid.SummaryofTranslation(or…soyouwanttomakeaProtein)Let’sbegininthenucleus……TheDNAhasthecodetoinstructtheRibosomesastowhichProteinstomake.Ok,2problemshere:1.)theDNAisintheNucleusandtheribosomesareintheCyto

6、plasm,and2.)theribosomescan’treadtheDNA.Wellthere’saneasywaytofixbothproblems…it’scalledTranscription….ThroughTranscription,theDNAcodeisplacedontoamRNAmoleculewhichcan1.)leavethenucleus,travelintothecytoplasmandjoinwiththeribosomes,and2.)theribosomescanTranslate(read)themRNA.SonowwehavetheDNAco

7、de,bywayofmRNA,inthecytoplasmthatcaninstructtheRibosomesastowhichproteintomake…..Bytheway,thedifferencebetweenoneproteinandanotherproteinistheorderoftheaminoacids,thenumberofaminoacidsandits3dimensionalshape.Now……let’ssayyouareari