Why is the hydrolysis of water necessary as it relates to photosystem 2 and the light-dependent reactions?

The lost e- that moved from photosystem 2 must be replaced.

So breakdown of water is important as it replace the lost e- .The e needed to replace those removed from photosystem 1 are proveided by photosystem2.So hydrolysis of water is associated with photosystem 2.

2H20---> 4H+ + 02 + 4e-

BRAINLIST PLS

the supermassive black hole is in the middle of the galaxy.