The oxygen produced in photosynthesis comes from what molecule?

Question

 ive been looking for an answer and i cant find one please help 

Answer 1

Hi, Lizz. This is a great question, because it ties together a lot of misconceptions. Briefly, we all know that it's chlorophyll that 'absorbs light', and so it must be electrons from chlorophyll that go dancing away to the electron transport chain.

 

But if we keep sending away electrons, we're going to run out! What to do?

 

Well, if you follow the numbers carefully, you will find that this is a balanced equation:

 

2H₂O => 4H⁺ + 4e^- + O₂

 

 

In other words, in the process of grabbing some electrons out of a water molecule, oxygen gas is generated as a waste product. So the oxygen comes from water.