A @[email protected] complex in plants and photosynthetic bacteria, responsible for light-harvesting and primary @[email protected] Comprises light-harvesting pigments such as chlorophyll; a primary electron-transfer centre, and secondary electron carriers. In green plant @[email protected], Photosystem I transfers electrons from plastocyanin to a [2Fe-2S] @[email protected], and contains @[email protected] Photosystem II transfers electrons from the oxygen-evolving complex to plastoquinone, and contains an iron centre.