Describe the Process of Chemiosmosis in the making of ATP

Chemisosmosis

In chemiosmosis, chloroplasts, protons (H+) are pumped through electron transfer to one side of the membrane, creating a gradient, which then allows them to diffuse back across through ATP synthase. This process allows ATP to be produced from ADP + P.

In chloroplast, the H+ are pumped into the thylakoid membrane space and then diffuse back out to the stroma. This causes ATP (like NADPH) to be produced in the stroma, which makes it readily available for the Calvin cycle.

An increase in light causes an increase in the amount of H+ that is pumped into the thylakoid membrane. The pH gradient will not occur if there is no light, as the process needs light energy to work.