- Translation occurs in 3 steps; initiation, elongation, and termination. During initiation, mRNA binds to a ribosome subunit which then binds to another ribosome subunit. The ribosome subunit then scans the mRNA for a start sequence which begins translation. Next, during elongation, the ribosome subunit holds the mRNA in place while complementary tRNA is attached to the binding sites. mRNA contains a 3 letter code called a codon while the tRNA contains a complementary code called an anti codon. Each codon is specific to one of the 20 amino acids. tRNA binds to the “P” site, while another tRNA binds to the “A” site. This binding causes change which results in the amino acid letting go of the tRNA and binding to the neighbouring amino acid. Then, the empty tRNA leaves the ribosome as it moves along the mRNA. As the ribosome moves along, the 2nd tRNA goes to the “P” site and new tRNA binds to mRNA at the “A” site. Finally, termination occurs which is when the mRNA reads a stop codon which does not have a matching tRNA. This codon puts an end to the elongation cycle, and since no new amino acid is added to the chain, the ribosome dissociates into its 2 subunits and the polypeptide is released.
- The model did a good job of showing every step clearly and what happened during those steps. There was nothing majorly inaccurate about the model.
Tons of detail in this one. I can’t really find anything that’s needs to be changed or corrected. You explained each step individually and in fine detail.