1、基因指导蛋白质的合成1. mRNA(信使 RNA） Messenger RNAs-are the nucleic acids that “record“ information from DNA in the cell nucleus and carry it to the ribosomes and are known as messenger RNAs (mRNA). （ 功能：作为编码蛋白质中氨基酸的模板 ）2.rRNA (核糖体 RNA） Ribosomal RNAs-exist outside the nucleus in the cytoplasm of a cell in str
2、uctures called ribosomes Ribosomes are small, granular structures where protein synthesis takes place. Each ribosome is a complex consisting of about 60% ribosomal RNA (rRNA) and 40% protein. (功能： 核糖体的 组成结构的一部分）3. tRNA (转运 RNA） Transfer RNAs-The function of transfer RNAs (tRNA) is to deliver amino a
3、cids one by one to protein chains growing at ribosomes. （ 功能： 转运氨基酸）Translation is the process by which the genetic messages carried by mRNA are decoded and used to build proteins in the cytoplasm1.Station cytoplasm2.Templet mRNA3.Material amino acids4.Products proteinsA set of three nucleotide base
4、s on an mRNA molecule is called a codon.(翻译是在细胞质中进行的。它是指以信使 RNA为模板，合成具有一定氨基酸顺序的蛋白质的过程。 ）(场所；细胞质 )( 模板：信使 RNA)(原料：氨基酸 )( 产物：蛋白质 )(信使 RNA上决定一个氨基酸的三个相邻的碱基叫一个密码子）U CAU G A U UAmRNACODON CODON CODON1. Each codon specifies a single amino acid .For example,CGC encodes arg.(一个密码子编码一个氨基酸，例如 CGC编码精氨酸）2.大多数氨基酸有多个密码子，例如， GUU， GUA都编码缬氨酸3.AUG（编码甲硫氨酸）为起始密码子，翻译从此密码子开始，少数起始密码子为 GUG
