At the most basic level, in order to produce oxygen and a carbohydrate (comprised of carbon, hydrogen, and oxygen), carbon dioxide must react with water as a source of hydrogen.
In order to construct carbohydrate molecules (often glucose) and release oxygen into the atmosphere, photosynthesis utilises carbon dioxide and water. Photosynthesis occurs in organelles called chloroplasts found in eukaryotic autotrophs like plants and algae.
Commonly used notation for photosynthesis is:
6CO + 6H
O C
H
O
+ 6O
This indicates that the reactants, six carbon dioxide molecules and six water molecules, are transformed into a sugar molecule and six oxygen molecules, the products, by light energy being absorbed by chlorophyll.
Learn more about water here:
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