Question

Which of the following is not Ribozyme?

• A. Ploy A polymerase
• B. Ribonuclease
• C. Transpeptidase
• D. Peptidyl Transferase

Answer 1

The Correct Option is A

Step 1: Ribozymes are defined by being RNA, not protein, yet still catalysing a reaction. The famous example is the ribosome itself forming peptide bonds.
Step 2: Polyadenylation tags the 3' end of an mRNA with many adenine bases. The machine that performs this, poly A polymerase, is a polypeptide enzyme, placing it firmly in the protein-enzyme camp.
Step 3: The remaining options reflect RNA-mediated catalysis: peptidyl transferase activity resides in ribosomal RNA, and RNase P uses an RNA component for cleavage.
Step 4: The odd one out, being a protein enzyme rather than catalytic RNA, is poly A polymerase.\[\boxed{\text{Poly A polymerase}}\]