AP BIOLOGY

Detailed explanation-1: -The energy in the proton electrochemical gradient is used to make ATP. The coupling of the electrochemical gradient of H+ across the inner mitochondrial membrane with ATP synthesis is called chemiosmotic coupling (because there is a concentration difference across the membrane and an electric potential).

Detailed explanation-2: -The proton gradient produced by proton pumping during the electron transport chain is used to synthesize ATP. Protons flow down their concentration gradient into the matrix through the membrane protein ATP synthase, causing it to spin (like a water wheel) and catalyze conversion of ADP to ATP.

Detailed explanation-3: -This difference is a hydrogen ion, or proton, concentration gradient. The energy associated with this gradient is used to synthesize ATP from ADP and Pi.