The supply of electrons in photosynthesis comes from water.
The splitting of water.
why are electrons important to photosynthesis.
It is produced from water. Water is broken down by photolysis to get electrons.
Water 
Photolysis.
The flow of electrons in photosynthesis has four sequential steps. Here is the sequence: from water to photosystem II then photosystem I and lastly NADP.
sunlight to excite the electrons
why are electrons important to photosynthesis.
No it does not. But photosynthesis provides electrons
It is produced from water. Water is broken down by photolysis to get electrons.
The splitting of water by the process of photolysis in photosystem II. There the electrons and protons are used in the process of photosynthesis but oxygen gas is a byproduct that diffuses out of the stomata into the atmosphere.
The electrons come from water. In the light dependent stage water is split into hydrogen ions (H+), electrons and oxygen. The electrons are passed on to chlorophyll, the H+ ions combine with NADP to form NADPH and the oxygen is released.
Food and oxygen
no
What are the products that come outof photosynthesis
What are the products that come outof photosynthesis
If the light is over, photosynthesis process will stop.
Carbohydrates