PS I and PS II occur over

PS I and PS II occur over the Grana of the chloroplast.
Photosystem I is an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin. It is an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane grana from plastocyanin to ferredoxin.
Photosystem II is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. It is located in the thylakoid membrane grana of plants, algae, and cyanobacteria.