英汉对照分子生物学导论Chapter 2.ppt

1、Nucleic acids: the information carrier,Information for making proteins is stored in nucleic acids.,Proteins,Nucleic acids (mainly DNA),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 (Ribonuc

2、leic 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,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

3、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。,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 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 / 它必须是稳定的,Age: 15 Age: 45 Age: 75,No change !,No change !,3. It must have some c

4、apacity for change3它必须具有容忍变化的能力,It must have some capacity for change它必须具有容忍变化的能力,It must be able to be copied4它必须能够被复制,2.2 Nucleic Acids and DNA structure2.2 核酸与DNA结构,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.,1) N

5、itrogenous base / 含氮碱基,2) Sugar / 糖,No oxygen here !,Ribonucleotides and deoxyribonucleotides核糖核苷酸 与 脱氧核糖核苷酸,3) Triphosphate/ 三磷酸,2.2.2 General Structure of Nucleic Acids2.2.2 核酸的一般结构,deoxyribonucleic acid ( DNA ),ribonucleic acid ( RNA ),Phosphodiester bond / 磷酸二酯键,Three prime end and five prime en

6、d三一撇末端 与 五一撇末端,Sugar-phosphate backbone / 糖-磷酸骨架,Nucleosome / 核小体,Chapter 7,2.2.3 Structure of DNA / 2.2.3 DNA的结构,Double-stranded DNA,Hydrogen bonds,Base pair / 碱基对,Complementary base pairs,Antiparallel DNA strands反向平行的DNA链,The DNA double Helix / DNA双螺旋,Minor groove,Major groove,2 nanometers,1 turn

7、= 10 bases = 3.4 nanometers,Denaturation of DNA / DNA变性,Light absorbance by DNA,DNA对光的吸收,= 260nm,= 260nm,ssDNA,dsDNA,Now showingMacromolecules Nucleic Acids,File: biophoto7 Life Macromoleculs Nucleic Acids (3),2.3 DNA as the Genetic Material2.3 DNA作为遗传物质,Store information,Stable,Allow mutation,Easy

8、replication,1. Storing information / 保存信息,2. Stability / 稳定性,2) Covalent bonds are very strong,4) Double helix,3) Many hydrogen bonds,1) Bases are protected,3. Allowing mutation / 允许突变,Allowing mutation / 允许突变,Attack !,Allowing mutation / 允许突变,Evolution,4. Easy replication / 容易复制,2.4 DNA in the Cell

9、2.4 细胞中的DNA,Prokaryotic Chromosome / 原核生物的染色体,Eukaryotic chromosomes / 真核生物染色体,2.5 RNA (Ribonucleic Acid)2.5 RNA（核糖核酸）,RNA,DNA,RNA is less stable than DNARNA不如DNA稳定,RNA is usually in a single-stranded form.RNA通常以单链的形式存在,RNA as the genetic materialRNA用作遗传物质,Single- stranded RNA,RNA is also importantR

10、NA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 ?,Chromosome / 染色体,They found that the chromosome is: 60% protein 40% DNA Which one is the genetic material?,The transformation experiment / 转化实验,The Hershey-Chase experiment,Wh