ATP synthase is an enzyme that helps in generating ATP which is used for all cell activities. It is a globular protein having two subunits -a headpiece - F1 and integral base- F0 . The head part is the peripheral protein and the site for ATP synthesis. The integral base protein forms the channel for movement of proton across the inner membrane. The proton movement is coupled to the catalytic site of ATP synthesis. For every ATP produced, 2H+ passes through the F0 and into the matrix down the electrochemical gradient. For 12H+ , 6ATP will be synthesized.