Which one of the following enzymes is not a protein, but an RNA molecule: (A) Peptidyl transferase, (B) RNA polymerse, (C) Restriction endonuclease, (D) Reverse transcriptase
Answer is A. Some RNA molecules have intrinsic catalytic activity. The activity of these RNA enzymes, or ribozymes, often involves the cleavage of a nucleic acid. Two ribozymes are the peptidyl transferase that catalyzes peptide bond formation on the ribosome, and ribozymes involved in the RNA splicingRef: Harper 30th pg: 363