Here sunlight and water used to produce ATP and NADPH which are types of energy carries to be transferred to the light dependent reactions in the stroma. The"byproduct" of this process is oxygen (O2).
1. Sunlight hits chlorophyll in Photosystem II (PSII)
2.The electrons (e-) in PSII accepts this light and becomes"excited"and shoots up and out of PSII. At the same time water is broken into 2 and H+
3.The electrons (e-) start to move down across the thylakoid membrane toward the Photosystem I (PSI) in achin called Electron Transport Chian(ETC). This e-loses energy as it goes down the ETC. This energy is used to pump H+ from the outside to inside.
4. At Photosystem I (PSI) light hits PSI again energizing the e-.
5.These excited and energized e- are now captured by an unenergized molecule called NADP+. The H+ that was produced from water in step 2 binds with NADP+ with the help of the energized e- and now becomes NADPH (an energized molecule. Just like ATP) This NADPH moves out of the thylakoids and into the stroma for the Calvin cycle.
6.The ATP synthase with the help of H+ (from Step 2) because H+ power this ATP synthase binds a photosphate to ADP and becomes ATP (an energized molecule) that will now also move out of the thylakoids and into the stroma for the Calvin cycle.