This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
Electron transpo from cytochrome &;b&; to cytochrome &;c&; is inhibited by 
Select and explain. 
A. Oligomycin, B. Antimycin, C. Piericidin, D. Carbon monoxide
B: Antimycin
Answer: B: Antimycin 
Explanation: Site II: This involves the transfer of electrons from Cytb-Cyt-c1. This step, as well as the previous one, is bypassed in the oxidation of L-ascorbate whose electrons are directly transferred to Cyt-c. This step is blocked by BAL, Antimycin A, Hypoglycaemic drug like phenformin.Ref: MN Chatterjea Textbook of Medical Biochemistry, 8th edition, page no: 143