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,1,/50,Nucleic acids:the information carrier,Information for making proteins is stored in,nucleic acids,.,Proteins,Nucleic acids,(mainly DNA),Nucleic acids:the information,Chapter 2 Nucleic acids,2.1 Properties of a Genetic,Material,2.2 Nucleic Acids and DNA,structure,2.3 DNA as the Genetic Material,2.4 DNA in the Cell,2.5 RNA(Ribonucleic Acid),2.6 Experiments,2.1 遗传物质的性质,2.2 核酸与DNA结构,2.3 DNA作为遗传物质,2.4 细胞中的DNA,2.5 RNA（核糖核酸）,2.6 实验研究,Chapter 2 Nucleic acids,2.1 Properties of a Genetic Material,It must be able to hold information for how to make proteins.,It must be stable.,It must have some capacity for change.,It must be able to be copied.,它必须能够保持如何生产蛋白质的信息。,它必须是稳定的。,它必须具有容忍变化的能力。,它必须能够被复制。,2.1 Properties of a Genetic M,It must be able to hold information for how to make proteins,1它必须能够保持如何生产蛋白质的信息,It must be able to hold inform,It must be stable,/2它必须是稳定的,Lizard:1,000,000 B.C.,Lizard:2008 A.D.,No change!,It must be stable /2它必须是,It must be stable,/它必须是稳定的,Age:15 Age:45 Age:75,No change!,No change!,It must be stable /它必须是稳定,3.It must have some capacity for change,3它必须具有容忍变化的能力,3.It must have some capacity,It must have some capacity for change,它必须具有容忍变化的能力,M,U,T,A,t,i,O,n,It must have some capacity for,It must be able to be copied,4它必须能够被复制,It must be able to be copied4,2.2 Nucleic Acids and DNA structure,2.2 核酸与DNA结构,2.2 Nucleic Acids and DNA str,2.2.1 Nucleotides,/,2.2.1 核苷酸,Nucleotides are composed of three parts:,1)a nitrogenous base,2)a sugar,and,3)a triphosphate.,N-glycosidic bond,2.2.1 Nucleotides/2.2.1 核,1)N,itrogenous base,/含氮碱基,1)Nitrogenous base /含氮碱基,2)Sugar /,糖,No oxygen here!,2)Sugar /糖No oxygen here!,Ribonucleotides and,deoxy,ribonucleotides,核糖核苷酸 与,脱氧,核糖核苷酸,Ribonucleotides and deoxyribon,3)Triphosphate,/三磷酸,3)Triphosphate/三磷酸,2.2.2 General Structure of Nucleic Acids,2.2.2 核酸的一般结构,d,eoxyribo,n,ucleic,a,cid,(,DNA,),r,ibo,n,ucleic,a,cid,(,RNA,),2.2.2 General Structure of Nu,P,hosphodiester bond,/磷酸二酯键,Phosphodiester bond /磷酸二酯键,T,hree prime end,and,five prime end,三一撇末端,与,五一撇末端,Three prime end and five prime,Sugar-phosphate backbone/,糖-磷酸骨架,Negative,charges,Sugar-phosphate backbone/糖-磷,Nucleosome,/核小体,Chapter 7,Nucleosome /核小体Chapter 7,2.2.3 Structure of DNA,/2.2.3 DNA的结构,Double-stranded DNA,Hydrogen bonds,2.2.3 Structure of DNA /2.,Base pair,/碱基对,Complementary base pairs,Base pair /碱基对Complementary,Antiparallel DNA strands,反向平行的DNA链,Antiparallel DNA strands反向平行的,The DNA double Helix /,DNA双螺旋,Minor,groove,Major,groove,2 nanometers,1 turn,=10 bases,=3.4 nanometers,Base stacking,The DNA double Helix /DNA,Denaturation of DNA /,DNA变性,Denaturation of DNA /DNA变性,Light absorbance by DNA,DNA对光的吸收,=260nm,=260nm,ssDNA,dsDNA,Light absorbance by DNADNA对光的吸,Now showing,Macromolecules Nucleic Acids,File:biophoto7 Life,Macromoleculs Nucleic Acids(3),Now showingMacromolecules N,2.3 DNA as the Genetic Material,2.3 DNA作为遗传物质,Store,information,Stable,Allow,mutation,Easy,replication,2.3 DNA as the Genetic Materi,1.Storing information /保存信息,1.Storing information /保存,2.Stability,/稳定性,2)Covalent,bonds are,very strong,4)Double,helix,3)Many,hydrogen,bonds,1)Bases are,protected,2.Stability /稳定性2)Covale,3.Allowing mutation,/允许突变,Chapter 9,3.Allowing mutation /允许突变,Allowing mutation,/允许突变,Attack!,Allowing mutation /允许突变Atta,Allowing mutation,/允许突变,Evolution,Allowing mutation /允许突变Evol,4.Easy replication,/容易复制,4.Easy replication /容易复制,2.4 DNA in the Cell,2.4 细胞中的DNA,2.4 DNA in the Cell2.4 细胞中的,Prokaryotic Chromosome /,原核生物的染色体,Prokaryotic Chromosome /原核生,Eukaryotic chromosomes,/,真核生物染色体,Nucleus,Eukaryotic chromosomes /真核生,2.5 RNA(Ribonucleic Acid),2.5 RNA（核糖核酸）,RNA,DNA,2.5 RNA(Ribonucleic Acid)2.,RNA is less stable than DNA,RNA不如DNA稳定,RNA is less stable than DNARN,RNA is usually in a single-stranded form.,RNA通常以单链的形式存在,RNA is usually in a single-str,RNA as the genetic material,RNA用作遗传物质,Single-,stranded,RNA,RNA as the genetic materialRN,RNA is also important,RNA也很重要,RNA is also importantRNA也很重要,2.6 Experiments /实验研究,Conclusion from studies in 19th century:,Chromosomes carry the genetic material!,But what is a chromosome,made of?,2.6 Experiments /实验研究Concl,Chromosome,/染色体,They found that the chromosome is:,60%protein,40%DNA,Which one is the genetic material?,Chromosome /染色体They found t,The transformation experiment,/转化实验,The transformation experiment,The Hershey-Chase experiment,The Hershey-Chase experiment,What is injected?,/注射的是什么？,Only DNA is injected!,What is injected?/注射的是什么？Onl,How did they know?,/他们是怎么知道的？,How did they know?/他们是怎么知,How did they know?,/他们是怎么知道的,How did they know?/他们是怎么知,DNA was the genetic material,DNA是遗传物质,DNA,Protein,DNA was the genetic materialD,
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