Question

Penicillin inhibits bacterial multiplication because it

• A. Inhibits cell wall formation
• B. Destroys chromatin
• C. Checks DNA synthesis
• D. Checks RNA synthesis

Answer 1

The correct option is A Inhibits cell wall formation

Mechanism of action of antibiotics
Antibiotics usually act against bacteria resulting in their reduced growth (bacteriostatic) or in their death (bactericidal). Some of their possible modes of actions are as follows:

• Inhibition of cell wall synthesis
• Inhibition of certain metabolic reactions such as:

1) Protein synthesis
2) Nucleic acid synthesis etc.

Mechanism of action of penicillin
Penicillin usually acts against gram positive bacteria that contain peptidoglycan in their cell wall. Penicillin inhibits the enzyme transpeptidase that catalyses the cross linking of peptidoglycan. Thus, the cell wall synthesis is inhibited.

Final answer :
(D) Inhibits cell wall formation