Aminoacyl t-RNA is required for all except -: (A) Hydroxyproline, (B) Methionine, (C) Cystine, (D) Lysine
Answer is A. Hydroxyproline and hydroxylysine are not represented into genetic code, i.e. they to not have t-RNA capable of accepting them and inserting them into polypeptide chain. Therefore, they have to be synthesized post-translationally from proline and lysine residues in the polypeptides.