Which component drives ATP synthase to phosphorylate ADP to ATP?

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Multiple Choice

Which component drives ATP synthase to phosphorylate ADP to ATP?

The energy that drives ATP synthase comes from the proton motive force across the inner mitochondrial membrane, which is made up of both a proton concentration gradient and the inner-membrane electrical potential. The electron transport chain pumps protons to the intermembrane space, creating this gradient. Protons then flow back through the F0 portion of ATP synthase, and that movement spins the rotor so the F1 catalytic sites convert ADP and inorganic phosphate into ATP. Without this proton-driven force, ATP synthase can’t efficiently make ATP, even though NADH oxidation powers the gradient and the gradient depends on oxygen as the terminal electron acceptor. Direct phosphorylation by ATP wouldn’t drive the reaction, since ATP would need energy from somewhere else to form ATP in the first place. The proton gradient and membrane potential are the direct energy source powering ATP synthesis.

The energy that drives ATP synthase comes from the proton motive force across the inner mitochondrial membrane, which is made up of both a proton concentration gradient and the inner-membrane electrical potential. The electron transport chain pumps protons to the intermembrane space, creating this gradient. Protons then flow back through the F0 portion of ATP synthase, and that movement spins the rotor so the F1 catalytic sites convert ADP and inorganic phosphate into ATP. Without this proton-driven force, ATP synthase can’t efficiently make ATP, even though NADH oxidation powers the gradient and the gradient depends on oxygen as the terminal electron acceptor. Direct phosphorylation by ATP wouldn’t drive the reaction, since ATP would need energy from somewhere else to form ATP in the first place. The proton gradient and membrane potential are the direct energy source powering ATP synthesis.

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