分子生物學(xué)英文版教學(xué)課件：Chapter 2 Nucleic acids

Nucleicacids:theinformationcarrierInformationformakingproteinsisstoredinnucleicacids.ProteinsNucleicacids(mainlyDNA)Chapter2Nucleicacids2.1PropertiesofaGeneticMaterial2.2NucleicAcidsandDNAstructure2.3DNAastheGeneticMaterial2.4DNAintheCell2.5RNA(RibonucleicAcid)2.6Experiments2.1遺傳物質(zhì)的性質(zhì)2.2核酸與DNA結(jié)構(gòu)2.3DNA作為遺傳物質(zhì)2.4細(xì)胞中的DNA2.5RNA（核糖核酸）2.6實(shí)驗(yàn)研究2.1PropertiesofaGeneticMaterialItmustbeabletoholdinformationforhowtomakeproteins.Itmustbestable.Itmusthavesomecapacityforchange.Itmustbeabletobecopied.它必須能夠保持如何生產(chǎn)蛋白質(zhì)的信息。它必須是穩(wěn)定的。它必須具有容忍變化的能力。它必須能夠被復(fù)制。Itmustbeabletoholdinformationforhowtomakeproteins

1．它必須能夠保持如何生產(chǎn)蛋白質(zhì)的信息Itmustbestable/2．它必須是穩(wěn)定的Lizard:1,000,000B.C.Lizard:2008A.D.Nochange!Itmustbestable/它必須是穩(wěn)定的Age:15Age:45Age:75Nochange!Nochange!3.Itmusthavesomecapacityforchange

3．它必須具有容忍變化的能力Itmusthavesomecapacityforchange

它必須具有容忍變化的能力MUTAtiOnItmustbeabletobecopied

4．它必須能夠被復(fù)制2.2NucleicAcidsandDNAstructure

2.2核酸與DNA結(jié)構(gòu)2.2.1Nucleotides /2.2.1核苷酸Nucleotidesarecomposedofthreeparts:1)anitrogenousbase,2)asugar,and3)atriphosphate.N-glycosidicbond1)Nitrogenousbase

/含氮堿基2)Sugar/糖Nooxygenhere!Ribonucleotidesanddeoxyribonucleotides

核糖核苷酸與脫氧核糖核苷酸3)Triphosphate

/三磷酸2.2.2GeneralStructureofNucleicAcids

2.2.2核酸的一般結(jié)構(gòu)deoxyribonucleicacid(DNA)ribonucleicacid(RNA)Phosphodiesterbond

/磷酸二酯鍵Threeprimeend

andfiveprimeend

三一撇末端與

五一撇末端Sugar-phosphatebackbone/糖-磷酸骨架NegativechargesNucleosome

/核小體Chapter72.2.3StructureofDNA/2.2.3DNA的結(jié)構(gòu)Double-strandedDNAHydrogenbondsBasepair/堿基對(duì)ComplementarybasepairsAntiparallelDNAstrands

反向平行的DNA鏈TheDNAdoubleHelix/DNA雙螺旋MinorgrooveMajorgroove2nanometers1turn=10bases=3.4nanometersBasestackingDenaturationofDNA/DNA變性LightabsorbancebyDNADNA對(duì)光的吸收λ=260nmλ=260nmssDNAdsDNANowshowing

Macromolecules–NucleicAcidsFile:biophoto7\Life\Macromoleculs–NucleicAcids(3’)2.3DNAastheGeneticMaterial

2.3DNA作為遺傳物質(zhì)StoreinformationStableAllowmutationEasyreplication1.Storinginformation/保存信息2.Stability/穩(wěn)定性2)Covalentbondsareverystrong4)Doublehelix3)Manyhydrogenbonds1)Basesareprotected3.Allowingmutation/允許突變Chapter9Allowingmutation/允許突變Attack!Allowingmutation/允許突變Evolution4.Easyreplication/容易復(fù)制2.4DNAintheCell

2.4細(xì)胞中的DNAProkaryoticChromosome/原核生物的染色體Eukaryoticchromosomes/

真核生物染色體Nucleus2.5RNA(RibonucleicAcid)

2.5RNA（核糖核酸）RNADNARNAislessstablethanDNA

RNA不如DNA穩(wěn)定RNAisusuallyinasingle-strandedform.

RNA通常以單鏈的形式存在RNAasthegeneticmaterial

RNA用作遺傳物質(zhì)Single-strandedRNARNAisalsoimportant

RNA也很重要2.6Experiments/實(shí)驗(yàn)研究Conclusionfromstudiesin19thcentury:Chromosomescarrythegeneticmaterial!Butwhatisachromosomemadeof?Chromosome/染色體Theyfoundthatthechromosomeis:60%protein40%DNAWhichoneisthegeneticmaterial?Thetransformationexperiment/轉(zhuǎn)化實(shí)驗(yàn)TheHershey-Chaseexperime