question_answer

(i) How many codons code for amino acids and how many do not?

(ii) Explain aminoacylation of the tRNA.

Answer:

(i) Out of 64 codons, 61 codons code for amino acids and rest 3 codons do not code for any amino acids. These function as stop codons.

(ii) Aminoacylation of the tRNA It is also called as charging of tRNA. It is the first phase of translation where amino acids are activated in the presence of ATP and linked to their cognate tRNA.

In the presence of ATP and\[M{{g}^{2+}}\], amino acids become activated by binding with aminoacyl tRNA synthetase enzyme.

\[Amino\,\,acid+ATP\xrightarrow[M{{g}^{\,2+}}]{Aminoacyl+RNA\,\,synthetase}AA-AMP-Enzyme\,\,complex+PPi\]