IMAT Chemiosmosis and ATP synthase questions
14 questions · Biology
How the proton gradient across a membrane drives ATP synthase, in mitochondria and in chloroplasts, and what uncouplers and inhibitors do to it.
Sample questions
- An uncoupler such as 2,4-dinitrophenol carries protons across the membrane outside ATP synthase. The result is:
- AOxygen consumption falls to zero, because the proton gradient is no longer being maintained
- BElectron transport accelerates, oxygen consumption rises, and the energy is released as heat instead of ATP
- CElectron transport stops and the cell cools down, because no energy is extracted from NADH
- DATP synthesis rises sharply, because protons now cross the membrane at many more sites than before and each one drives the synthase
- EThe chain begins to work in reverse, reducing NAD+ with electrons taken from water
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