Aproton gradient is established with the buildup of hydrogen ions on one side of the inner membrane of the mitochondria in eukaryotes. the protons can get back to the matrix by passing through what enzyme?

a. rubisco
b. atp synthase
c. etc phosphotase

B. ATP synthase. The purpose of the hydrogen gradient is to take advantage of molecules' tendency to move from areas of higher concentration to areas of lower concentration. ATP synthase lets hydrogen ions flow through it to the matrix, and the energy from this flow is used by ATP synthase to synthesize ATP.