What drives the ATP synthase reactions that produce ATP? the redox reaction that changes NADH to NAD + the energized electrons from the electron transport chain the formation of water at the end of the electron transport chain the hydrogen ion concentration gradient across the membrane

At the electron transport chain, hydrogen is built up on one side of the electron transport chain and the electrons which are their way down the chain are building up on the other side. The electrons and hydrogen are attracted to each other due to their charges. These for the hydrogen flows though the gradient in the membrane to reach the elections. Once the hydrogens pass though this gradient it produces the ATP from the hydrogen "turning" the protein. At the end the oxygen is placed at the bottom of the electron transport chain to accept the hydrogen which makes water.

adding a phosphate group to ADP.