Question:
NADH-CoQ reductase is inhibited by?
NADH-CoQ reductase is inhibited by?
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Which insecticide is the classic Complex I blocker?
Updated On: Jun 24, 2026
- Rotenone
- Carbon monoxide
- Antimycin
- Atractyloside
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The Correct Option is A
Solution and Explanation
Step 1: NADH-CoQ reductase is Complex I of the electron transport chain. It carries electrons from NADH to coenzyme Q.
Step 2: Complex I is blocked by rotenone (an insecticide), along with barbiturates such as amobarbital, piericidin A, chlorpromazine and guanethidine. These agents stop electron flow from the iron-sulfur protein to coenzyme Q. So rotenone is the correct inhibitor.
Step 3: Carbon monoxide (option b) inhibits Complex IV (cytochrome c oxidase). Antimycin (option c) inhibits Complex III. Atractyloside (option d) inhibits the ADP-ATP translocase, not Complex I.
Step 4: Since rotenone is the classic Complex I (NADH-CoQ reductase) inhibitor, option a is correct.
Step 2: Complex I is blocked by rotenone (an insecticide), along with barbiturates such as amobarbital, piericidin A, chlorpromazine and guanethidine. These agents stop electron flow from the iron-sulfur protein to coenzyme Q. So rotenone is the correct inhibitor.
Step 3: Carbon monoxide (option b) inhibits Complex IV (cytochrome c oxidase). Antimycin (option c) inhibits Complex III. Atractyloside (option d) inhibits the ADP-ATP translocase, not Complex I.
Step 4: Since rotenone is the classic Complex I (NADH-CoQ reductase) inhibitor, option a is correct.
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