IMAT The electron transport chain questions

Sample questions

1. 1IMAT Doutor

   In an isolated mitochondrion supplied with substrate and oxygen but no ADP, electron transport slows almost to a stop. Adding ADP restores it immediately. What does this show?
   1. AADP is a direct substrate of complex I, which cannot accept electrons from NADH unless ADP is bound to it first
   2. BOxygen cannot be consumed in the absence of ADP, because complex IV uses ADP rather than oxygen as the final acceptor of the electrons that pass along the chain
   3. CADP is required to keep the inner membrane intact, and without it the membrane leaks until the chain can no longer function
   4. DThe chain runs backwards when there is no ADP, oxidising water and reducing NAD⁺, until ADP is supplied again
   5. EElectron transport is coupled to ATP synthesis: without ADP the gradient cannot be discharged, and the accumulated proton-motive force opposes further pumping
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2. 2IMAT 2025 Q13

   Oxidative phosphorylation is a metabolic pathway:
   1. Athrough which fatty acid synthesis occurs
   2. Bthrough which fatty acids are broken down by removing two carbon atoms at a time
   3. Cthrough which the amino group resulting from the degradation of amino acids is eliminated
   4. Dwhich represents the final stage of the anabolism of amino acids, carbohydrates, and fatty acids
   5. Ethrough which the energy stored in reduced coenzymes is used for the synthesis of ATP
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