What is the function of water in photosynthesis?

2 Answers
Aug 24, 2015

It doesn't necessarily have a function, but is a molecule that reacts with carbon dioxide to produce glucose.


Water is one of the reactants in photosynthesis, it provides the hydrogen needed to form glucose (a hydrocarbon).

#"carbon dioxide" + "water" + "energy" -> "glucose" + "oxygen"#
#6"CO"_2 + 6"H"_2"O" -> "C"_6"H"_12"O"_6 + 6"O"_2#

Water and carbon dioxide enter the leaf through the stomata (small holes on the underside of the leaf that are controlled by gaurd cells) by diffusion.

The water is split during the light reaction to form oxygen gas and hydrogen ions. The hydrogen ions are used by the chloroplast to produce ATP.


The hydrogen is also important because it can combine with carbon (from carbon dioxide) to produce glucose.

Here is a video which provides a quick summary of photosynthesis.

Video from: Noel Pauller

Hope this helps!