文档介绍：(3) 、核酸蛋白质是生物体用以表达各项功能的具体工具,而核酸是生物用来制造蛋白质的模型。没有核酸,就没有蛋白质。因此,核酸是最根本的生命的物质基础。它是生物体的遗传物质核酸( RNA , DNA ) 核苷酸磷酸核苷戊糖(核糖或脱氧核糖) 碱基( A,T,C,G A,G,C,U) 核酸由核苷酸经过脱水而得,即核苷酸是核酸的单体。 RNA:R为 OH碱基为 C、 A、 G和 U DNA:R为 H碱基为 C、 A、 G和 T OH POO CH 2 OH R HO O碱基戊糖磷酸核苷酸分子结构式核酸 DNA RNA 核苷酸(基本单元) 腺嘌呤脱氧核苷酸鸟嘌呤脱氧核苷酸胞嘧啶脱氧核苷酸胸腺嘧啶脱氧核苷酸腺嘌呤核苷酸鸟嘌呤核苷酸胞嘧啶核苷酸尿嘧啶核苷酸碱基腺嘌呤(A) 鸟嘌呤(G) 胞嘧啶(C) 胸腺嘧啶(T) 腺嘌呤(A) 鸟嘌呤(G) 胞嘧啶(C) 尿嘧啶(U) 戊糖 D-2- 脱氧核糖 D- 核糖酸磷酸磷酸 NN NH N NH 2HNN NH N OH 2N腺嘌呤( A)鸟嘌呤( G) NN NH 2O HNH OO HNN OO CH 3 H H H 胞嘧啶( C)胸腺嘧啶( T)尿嘧啶( U) 碱基 1957 (拖德) Sir Alexander R. Todd (Great Britain, * ) Great Britain, Cambridge University, " for his work on nucleotides and nucleotide co- enzymes" . 弄清了核酸的化学结构式------ 一级结构 1980 The Prize was divided, one half being awarded to: Paul Berg (USA, * ) USA, Stanford University, Stanford, CA, "for his fundamental studies of the biochemistry of nucleic acids, with particular regard to binant- DNA" ; and the other half jointly to: Walter Gilbert (USA, * ) USA, Biological Laboratories, Cambridge, MA, and Frederick Sanger (Great Britain, ) USA, Great Britain, MRC Laboratory of Molecular Biology, Cambridge, "for their contributions concerning the determination of base sequences in nucleic acids" . 单链 DNA 双链结合磷酸—糖链在外,碱基在里,一条链上的碱基与另一条链上的碱基以 H bond 的形式相互结合。其中又有什么规律呢?