Question

How many electrons,protons and photons are involved in lysis of water to evolve one molecule of oxygen?

Answer 1

Since we know that absorption of 1 photon of light by Photosystem II removes 1 electron from P680, it becomes oxidized.

• With its resulting positive charge, P680 is sufficiently electronegative that it can remove 1 electron from a molecule of water.
• When these steps have occurred 8 times, requiring 4 molecules of water, 2 molecule of oxygen and 8 protons (H+) are released.