Answer: Peptidyl transferase (part of the ribosome).
- A Peptidyl transferase (part of the ribosome)
- B DNA polymerase, which extends a nucleotide strand during replication
- C RNA polymerase, which synthesises mRNA from a DNA template
- D Topoisomerase, which relieves supercoiling tension in DNA
Correct answer: A. Peptidyl transferase (part of the ribosome)
Explanation: Peptidyl transferase, a ribozyme activity of the ribosomal RNA, catalyses peptide bond formation during translation.
Two amino acids join via a condensation reaction: the carboxyl -OH of one and an amine -H of the other are eliminated as water, leaving a peptide bond (-CO-NH-) linking them into a dipeptide; repeating this builds a full protein chain.
Concept context
The chemistry of life: carbohydrates, proteins, lipids, nucleic acids, enzymes, and vitamins. Understand their structures, classification, and biological functions. Highly relevant for NEET and Class 12 board exams.