Question

Site of action of amphotericin B is:

• A. Ribosomes
• B. Cell wall
• C. Plasma membrane
• D. Protein

Answer 1

The Correct Option is B

Step 1: Amphotericin B belongs to the polyene class. The defining trick of polyenes is that they latch onto a membrane sterol rather than attacking the wall, ribosomes or proteins.

Step 2: Its target is ergosterol, the cholesterol-like sterol embedded in the fungal plasma membrane. The drug binds this sterol and wedges itself into the lipid bilayer.

Step 3: Once inserted, several molecules line up to create a pore, so potassium and other contents leak out and the fungus dies. The whole action takes place at the plasma membrane.

\[\boxed{\text{Plasma membrane}}\]