Can we consider oxygen as a product of light dependent reactions?

Question

Julian Aguilar · Accepted Answer

Oxygen is normally considered a byproduct or waste product of the light dependent reactions since it isn't involved in the reactions of photosynthesis.

However, oxygen is a very valuable by/waste product, since all aerobic organisms require it for aerobic cellular respiration, including plants.

The image below shows the light independent reactions of photosynthesis at the thylakoid membrane of the chloroplast.

Julian Aguilar · Answer

Yes!

Oxygen is in fact a by product of light dependent reactions of photosynthesis.

During light reaction of photosynthesis, In non-cyclic electron flow, when Photosystem II absorbs light, an electron is excited to a higher energy level in the reaction center of Chlorophyll #P_680#. Thus a hole has been created in its reaction center & chlorophyll has become a very strong oxidizing agent. It's electron hole must be filled.

Thus an enzyme extracts electron from water, splitting the water molecule into two hydrogen ions and one oxygen atom. The oxygen atom abrubptly combine with another oxygen atom to form #O_2#. This reaction of photosynthesis during which xygen is produced is known as photolysis.* This oxygen produced is the main source for replenishment of atmospheric oxygen.
#H_2O# #to# #2H^+ + 2e^- + 1/2O_2#

Hope it helps!

Cooper Alexander · Answer

undefined No, oxygen is not directly produced in light-dependent reactions of photosynthesis. Oxygen is actually produced during the light-dependent reactions of photosynthesis through the process of photolysis, where water molecules are split into oxygen, protons, and electrons by the energy from light. The oxygen released is a byproduct of this process, not a direct product of the light-dependent reactions themselves.