Describe the Reduction and Oxidation that occurs in Photosynthesis

The main chemical reaction that takes place during photosynthesis is:

               (light)

6CO2 + 6H2O------------> (C6H12O6) + 6O2

"Plants breathe in carbon dioxide and breathe out oxygen". This is the overall chemical formula that shows how that works.

This reaction, however, is really the result of two separate processes.

1.      Splitting the Water Molecule

The chemical equation that shows the splitting of the water molecule is shown below:

               (light energy)

12 H2O -----------------------> 6 O2 + 24 H+ + 24e-

For every 12 molecules of water, 6 oxygen molecules are released. This is accompanied by the release of 24 hydrogen atoms and 24 electrons. Since the water molecule is losing electrons in this reaction, the water molecule is said to be oxidized.

2.      Conversation of Carbon Dioxide to Glucose

The chemical equation that shows the conversation of carbon dioxide to glucose is shown below:

CO2 + 24 H+ + 24 e- ------> C6H12O6 + 6 H2O

In this reaction, carbon dioxide, in the presence of hydrogen ions and electrons is converted to glucose and water. Since carbon dioxide is adding electrons, it is reduced.