MDCAT Biology MCQ #534

A toxin is found to block the transfer of electrons from cytochrome a3 to oxygen. Which of the following substances acts in this manner?

MDCAT Biology MCQ #534

  1. Question 1

    Q1. A toxin is found to block the transfer of electrons from cytochrome a3 to oxygen. Which of the following substances acts in this manner?

    • A) Rotenone
    • B) Antimycin
    • C) Cyanide
    • D) Oligomycin

    Answer: Cyanide

    Explanation: Cyanide blocks cytochrome a3, stopping the ETC. DNP is an uncoupler, while Oligomycin inhibits ATP synthase directly.