Stage One:
According to Rost, Barbour, Stocking & Murphy, 2006 “Chlorophyll in green plants absorbs light energy” (pp.148), this procees takes place via a series of light and temperature sensitive reactions which is expressed in the following formula: 6CO2 + 12H2O + Light Energy à C6H12O6 + 6O2 .This initial stage is known as the light reaction, while the remaining stages are known as the dark reactions. These dark reactions can occur at with or without light present, thus their name. O2 and H2O are byproducts of the stage.
Explained in this Diagram: