How does ATP synthase work?

ATP synthase binds to the F0 portion within the mitochondrial matrix or chloroplasts. The F0 portion essentially acts as a rotor, permitting protons to flow through the membrane from an area of high concentration to low concentration. ATP synthase also has a F1 portion, which is found in the mitochondrial matrix in humans or the thylakoid membrane of chloroplasts in plants. This portion uses the energy produced by the proton flow through the F0 portion to catalyze the synthesis of ATP from ADP and Pi. The F1 head is hexameric and is composed of alpha and beta proteins arranged in sets of dimers. The alpha subunit of ATP synthase in the F1 portion is found within the center of the alpha 3, beta 3 hexamer and undergoes a unidirectional rotation during ATP hydrolysis. ATP synthesis occurs within the beta subunits of the F1 head.