Chloroplasts generally have both cyclic and non-cyclic photophosphorylation—what's the difference?
In cyclic photophosphorylation, electrons go through the ETC and return to a chlorophyll in the same photosystem. A proton gradient is built across the thylakoid membrane and ATP synthase is used to produce ATP. In non-cyclic photophosphorylation, electrons go through a different ETC ending up in chlorophyll in a different photosystem (H+ ion gradient still formed, ATP made by chemiosmosis). Light is absorbed, and the electrons enter another ETC, ending up by reducing NADP into NADPH2, which then inters the Calvin cycle.