How does the proton motive force drive ATP production in ATP synthase?

• A. Protons flow through Fo of ATP synthase, causing rotation of the gamma shaft in F1, driving conformational changes that synthesize ATP from ADP and Pi; PMF provides the energy for this synthesis.
• B. Protons flow through Fo into the cytosol, with no rotation of a shaft.
• C. ATP synthesis is powered by random diffusion of ATP synthase.
• D. Rotation occurs independently of proton flow; PMF is unrelated.

Answer: (C)