Question

For each of the following tRNA anticodon sequences, determine which amino acid would be charged onto the tRNA. (note: these are ANTIcodon sequences, not codon sequences) If more than one tRNA is necessary to recognize all codons for that amino acid, state the anticodon sequences of the other tRNAs that would also be charged with that amino acid. If a given sequence is not a possible tRNA anticodon sequence, explain why not.

A. 5’- IAU - 3’

B. 5’- GCC - 3’

C. 5’- CCG - 3'

D. 5’- UAU - 3’

E. 5’- AGG - 3’

F. 5’- ICA - 3’

Now, for any one of the possible tRNAs, sketch a ribosome with the charged tRNA interacting with an appropriate codon in the A site. Then show two things that must happen before that tRNA can be found in the ribosome’s P-site.

Answer 1

The A with t-RNA anticodon 5'-IAU-3' and F with t-RNA anticodon 5'-ICA-3' is not a possible t-RNA anticodon sequence because the t-RNA sequence can be formed by using only 4 nitrogenous bases A,U(T in DNA in place of U),G,C

and here I is not a nitrogenous base so it is not possible.

The sketch of ribosome with the charged t-RNA interacting with appropriate codon in the A site is given below:

The things that must happen before that t-RNA can be found in ribosome's P site is accomodation and movement of amino acid chain from t-RNA in P site to the t-RNA on A site and then the empty t-RNA on p site will move to E site then move out from the ribosome and the t-RNA from A site will move to P site by accomodation.