What is the main function of the proton gradient in ATP synthesis?

This proton gradient is important because it is the breakdown of this gradient that leads to the synthesis of ATP. The gradient is broken down due to the movement of protons across the membrane to the stroma through the transmembrane channel of the CF0 of the ATP synthase. The ATP synthase enzyme consists of two parts: one called the CF0 is embedded in the thylakoid membrane and forms a transmembrane channel that carries out facilitated diffusion of protons across the membrane. The other portion is called CF1 and protrudes on the outer surface of the thylakoid membrane on the side that faces the stroma. The break down of the gradient provides enough energy to cause a conformational change in the CF1 particle of the ATP synthase, which makes the enzyme synthesise several molecules of energy-packed ATP.