Protein synthetic System Direct template-mRNA ●tRNA ●Ribosomes 20 amino acids (AA) ●Enzyme and protein factors:F、eF、EF、RF ·ATP、GTP、Mg2+ Characteristics:complicated,accurate, dynamic,quick,energy consumed (90%)
● 20 amino acids (AA) ● Enzyme and protein factors: IF、eIF、EF、RF ● ATP、GTP、Mg2+ Protein synthetic System ⚫ Direct template— mRNA ⚫ tRNA ⚫ Ribosomes Characteristics：complicated, accurate, dynamic,quick, energy consumed（90%）
S 1.1 Genetic codon carrier-mRNA ●base→amino acid conversion:Genetic code a three-nucleotide codon in a nucleic acid (mRNA) sequence specifies a single amino acid,initiatior codon or terminator codon.This kind of three-nucleotide codon is called genetic codon or triplet codon. Initiator codon:AUG Terminator codon:UAA、UAG、UGA
§1.1 Genetic codon carrier-mRNA ● base amino acid conversion：Genetic code a three-nucleotide codon in a nucleic acid (mRNA) sequence specifies a single amino acid, initiatior codon or terminator codon. This kind of three-nucleotide codon is called genetic codon or triplet codon. Initiator codon: AUG Terminator codon: UAA、UAG、UGA
Standard Genetic codon U A G UUU UCU UAU UGU Phe Cys U UUC UCC Tyr Ser UAC UGC UUA UCA UAA Stop UGA Stop UUG Leu 内 UCG UAG Stop UGG Trp CUU CCU- CAU His CGU U cUc CCC CAC CGc First Leu Pro Arg CUA CCA CAA Third position GIn CGA A CUG CCG CAG CGG G position (5'end) AUU U (3'end) ACU AAU AGU Asn A AUC ACC AAC Ser Thr AGC AUA ACA AAA Lys AGA Arg AUG ACG AAG AGG G GUU GCU GAUT Asp GGU ☑ G GUC Val GCC Ala GAC GGC GAA Gly GUA GCA Glu GGA GUG GCG GAG GGG G Amino acid names Ala alanine GIn glutamine Leu leucine Ser serine Arg=arginine Glu glutamate Lys =lysine Thr threonine Asn =asparagine Gly glycine Met methionine Trp tryptophan Asp aspartate His histidine Phe phenylalanine Tyr Tyrosine Cys =cysteine Tle =Isolevcine Pro proline Val valine
Standard Genetic codon
Salient features Sense codon:code for amino acid -61. Nonsense codon:code for no amino acid-terminator codon-UAA,UAG,UGA Initiator codon as initiation signal for translation AUG,GUG(prokaryote)
Sense codon：code for amino acid — 61. Nonsense codon：code for no amino acid— terminator codon—UAA，UAG，UGA Initiator codon ：as initiation signal for translation — AUG, GUG(prokaryote) . Salient features
A complete sequence of mRNA,from the initiation codon (AUG)to the termination codon,is termed as the open reading frame_(ORF),which codes for the primary structure of polypeptide. ORF 5 AUG UAA 3 UTR UTR
A complete sequence of mRNA, from the initiation codon (AUG) to the termination codon, is termed as the open reading frame (ORF), which codes for the primary structure of polypeptide. 5 ' A U G U A A 3 ' ORF UTR UTR