Question

How does the cellular entity that is responsible for translation know what amino acid to hook on next to the growing polypeptide chain and what molecules help amino acids attach to growing peptides?

Answer 1

There are total 20 amino acids. The cell contain different t-RNA molecules having same function. t-RNA has complementary sequence of codon that allows the correct amino acid to be attached by reading the m RNA. t-RNA has characteristic cloverleaf like structure. All t- RNA fold in compact L shape essential to assemble with the ribosome during translation process. This t-RNA has one 3' terminal end sequence CCA. Amino acid covalently attache to the terminal adenosine of t-RNA. This charged t-RNA recognise the m-RNA codon sequence with the help of anticodon. Correct t-RNA fit into the ribosome by appropriate codon anticodon base pairing. Correct amino acid is added into the growing polypeptide chain.