("Photosynthesis - Biology-Online Dictionary") This process can be simplified to this equation: 6CO2+12H2O+energy=C6H12O6+6O2+6H2O. It means that photosynthesis is a process in which carbon dioxide (CO2), water (H2O) and light energy are used to synthesize an energy-rich carbohydrate such as glucose (C6H12O6) and to produce oxygen (O2) as a by-product. ("Photosynthesis - Biologia-Online