Photosynthesis: What Powers the Splitting of Water?

Question

The splitting of water is an endergonic (non-spontaneous) reaction, and thus would require energy (chemical work to be done) in order to happen.In Photosystem II, an enzyme catalyzes this splitting, but where does it get the energy from? Does it use ATP?

Answer 1

No. The energy for this comes from photons from the sunlight. This occurs through a process called the Joliot-Kok cycle.