《微生物学 Microbiology》课程PPT教学课件（英文版）microbial genetics 2/3

Chapter 8,part B Microbial Genetics

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B.E Pruitt & Jane J. Stein Chapter 8, part B Microbial Genetics

Translation DNA mRNA Ribosomal subunit tRNA Translation Protein Anticodon continues. Ribosomal subunit mRNA Components needed to begin translation come togettler. Figure 8.10.1

Translation Figure 8.10.1

Translation Ribosome continues. Start Second codon codon mRNA ② On the assembled ribosome,a tRNA carrying the first amino acid is paired with the start codon on the mRNA. A tRNA carrying the second amino acid approaches. Figure 8.10.2

Translation Figure 8.10.2

Translation Peptide bond forms P site Me A site continues. mRNA The place on the ribosome where the first tRNA sits is called the P site.In the A site next to it,the second codon of the mRNA pairs with a tRNA carrying the second amino acid. Figure 8.10.3

Translation Figure 8.10.3

Translation tRNA released Peptide bond AUGAUUAG continues. The first amino acid joins to the second by a peptide bond,and the first tRNA is released. Figure 8.10.4

Translation Figure 8.10.4

Translation P site 床 AUG continues. Ribosome moves mRNA along mRNA The ribosome moves along the mRNA until the second tRNA is in the P site,and the process continues. Figure 8.10.5

Translation Figure 8.10.5

Translation Growing polypeptide chain Phe continues. AsU0A©GuuU mRNA 6 The ribosome continues to move along the mRNA,and new amino acids are added to the polypeptide. Figure 8.10.6

Translation Figure 8.10.6

Translation %-eu Met Polypeptide Phe released Met Gly mRNA continues. A UG Stop codon When the ribosome reaches a stop codon,the polypeptide is released. Figure 8.10.7

Translation Figure 8.10.7

Translation GI Met Arg New protein mRNA ⊙ Finally,the last tRNA is released,and the ribosome comes apart. The released polypeptide forms a new protein. Figure 8.10.8

Translation Figure 8.10.8

Translation DNA mRNA Translation Protein TEM 200nm Direction of transcription RNA DNA polymerase Polyribosome Ribosome mRNA Direction of translation Figure 8.11

Translation Figure 8.11