1. Describe the process of translation: initiation, elongation, and termination.
Initiation. In this process, the mRNA binds to a small ribosome subunit which then leads to two ribosome subunits binding together.
Elongation. This is where the ribosome holds the mRNA and allows complimentary tRNA to attach to binding sites, specifically the “P” site and “A” site. The mRNA has a three-letter code called codon and the tRNA has a complementary coding called anticodon. The first tRNA binds to the “P” site and the second, binds to the “A” site which causing the amino acid to let go of tRNA and bind to the neighbouring amino acid. The empty tRNA then leaves the ribosome, the ribosome moves along the mRNA, and the 2nd tRNA arrives at “P” site and new tRNA binds to mRNA codon at the “A” site.
Termination. In this final stage of translation, the elongation cycle has continued until mRNA “reads” a STOP codon. This is a “3 letter word” which does not have a matching tRNA. Therefore, no new amino acid is added to the chain, which allows the ribosome to dissociate into its 2 subunits and the polypeptide is released.
2. How did today activity do a good job of modelling the process of translation? In what ways was our model inaccurate?
I found this example to be quite helpful in many ways, with few remaining gaps of clarification left. For instance, when first examining the process of translation, I found it quite difficult to fully comprehend how exactly this process worked and it was quite confusing however, as soon as we transitioned this to a hands-on activity, it became clear what the lesson was trying to illustrate. While this activity was successful in helping me understand the basic steps of translation, it was still unclear and could have been more accurate in a few areas. Some of those areas in particular being, demonstrating how exactly the tRNA binds to the ribosome, how the ribosome moves along the mRNA strand, as well as how the tRNA manages to stay bonded to the ribosome while transitioning from the “A” site to the “P” site.