What is the importance of water, oxygen, carbon dioxide during the photosynthesis process?
Water + carbon dioxide --> glucose + oxygen
Water and carbon dioxide are used in organisms which photosynthesise. The reactants in this equation are used to generate glucose needed for photosynthetic organisms to be able to respire. Oxygen is a bi-product and is used by organisms so they can respire.
Water and carbon dioxide are the starting materials for photosynthesis. Oxygen (along with glucose) are products of photosynthesis.
In order for plants to carry out the process of photosynthesis, they need water, carbon dioxide and light. The water and carbon dioxide are the reactants - materials present before the chemical change.
During the light reaction, chlorophyll molecules absorb light energy which is used to split water. This produces oxygen gas and hydrogen ions. The hydrogen ions are used by the chloroplast to produce ATP molecules.
During the dark reaction (Calvin cycle) the chloroplast uses carbon from carbon dioxide to produce three carbon molecules which can be assembled into glucose.
The overall equation for photosynthesis is:
Here is a video which shows an experiment which tests the rate of photosynthesis for plants with varying amounts of carbon dioxide available for the reaction.
Video from: Noel Pauller