The GATE Grind

GATE 2026 BT – Question 20

General Biology · Microbiology: Microbial diseases, host-pathogen interactions, antibiotics and resistance, two-component system, bacterial communication, viruses · 1 mark · Multiple choice

Which one of the following antibiotics blocks protein chain elongation by preventing the action of peptidyl transferase?

  1. Bleomycin
  2. Rifampicin
  3. Chloramphenicol
  4. Tetracycline

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (C) Chloramphenicol

Explanation

Chloramphenicol binds the 50S ribosomal subunit and inhibits the peptidyl transferase. Tetracycline blocks the binding of aminoacyl-tRNA to the A site, rifampicin inhibits RNA polymerase, and bleomycin damages DNA.