How does the electron transport chain convert NADH and FADH2 into ATP?
In order to get the full amount of energy released by the breakdown of sugar, you must convert the high energy molecules NADH and FADH2 into ATP. This occurs in the inner membrane of the mitochondria. Energy in the form of electrons is taken from these molecules and passed from molecule to molecule in a molecular game of “hot potato” until it is ultimately dumped on oxygen. The extra pair of electrons allows oxygen to make another chemical bond, and it makes a water molecule. This frees up the electron transport chain to take another pair of electrons from an FADH2 or a NADH.
