Questions: Multiple Choice Question Of the following antibiotics, which is an inhibitor of cell wall synthesis? rifampin penicillin tetracycline polymyxin

The answer is the second one (B): penicillin.

Explanation for each option:

• Rifampin: This antibiotic is not an inhibitor of cell wall synthesis. Instead, it works by inhibiting RNA synthesis in bacteria, specifically by binding to the bacterial RNA polymerase. Therefore, it is incorrect.

• Penicillin: This antibiotic is a well-known inhibitor of cell wall synthesis. It works by interfering with the synthesis of peptidoglycan, an essential component of the bacterial cell wall, leading to cell lysis and death. Therefore, it is correct.

• Tetracycline: This antibiotic inhibits protein synthesis by binding to the 30S ribosomal subunit, preventing the attachment of aminoacyl-tRNA to the ribosome. It does not affect cell wall synthesis. Therefore, it is incorrect.

• Polymyxin: This antibiotic disrupts the bacterial cell membrane by interacting with its phospholipids, leading to increased permeability and cell death. It does not inhibit cell wall synthesis. Therefore, it is incorrect.

In summary, penicillin is the antibiotic among the options that inhibits cell wall synthesis.