Polypeptide Elongation Cycles

Start the animation (1 frame/sec).

The animation shows the stepwise addition of four amino acids to an initiated fMet residue and ends with the dissociation of a pentapeptide from the ribosome. Individual steps are not labeled, but the "cast of characters" is listed in the last frame.
(See Campbell, Fig. 11.12 for a summary.)

Five Questions (you should be able to answer):
1. What are the various steps pictured for each amino acid addition?
2. Can you anticipate the next step during each cycle?
3. What are the protein factors that assist the various steps pictured?
4. When is GTP hydrolyzed?
5. What is different about chain termination?

Back to Lecture 22: Protein Synthesis: Ribosomes & Peptide Bond Formation.

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