Question

A smaller subunit of ribosome has a binding site for ______ and the larger subunit has two binding sites for tRNA molecules.

• A. Mg${}^{++}$
• B. Peptidyl transferase
• C. mRNA
• D. None of the above

Answer 1

The correct option is C mRNA

Peptidyl transferase is an enzyme that forms peptide bonds between adjacent amino acids with aid of tRNAs during the translation process of protein biosynthesis. Initiation of protein synthesis includes binding of mRNA to the smaller of two ribosomal subunits and to the initiating aminoacyl-tRNA. The large ribosomal subunit then binds to form an initiation complex to facilitate binding of charged tRNA during elongation of polypeptide chain. Thus, smaller subunit of ribosome has a binding site for mRNA and the larger subunit has two binding sites for tRNA molecules. Correct answer is C.