Well im not sure but this might helps... 1. light energy is absorbed by electrons in pigments and water molecules are split into H+ ions, oxygen, and electrons 2. high energy electrons move down the electron transport chain, where energy from electrons is used to pump h+ ions into thylakoid space 3. at end of chain, NADP+ molecules pick up the high energy electrons along with H+ ions to become NADPH 4. H+ ions in the thylakoid space pass thru apt synthase in the thylakoid membrane, causing the ATP synthase base to rotate and produce ATP