Answer:
The overall chemical equation of a photosynthesis can be written as:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Word equation: Carbon dioxide + water → Glucose + Oxygen
Photosynthesis is a process by which green plants make their food (glucose) from carbon dioxide and water in presence of sunlight and chlorophyll.
It can be broadly classified into two stages namely light-dependent reaction and light-independent reaction.
In light-dependent reaction, the photon-energy or the light energy is converted into the ATP and NADPH that is, the chemical energy. Water is photo-lysed to produce oxygen and high-energy electrons. The electrons are passed through the electron transport chain which help in the production of ATP and NADPH. Oxygen is released as a byproduct.
In light-independent reaction or dark reaction, energy in the form of ATP and NADPH is used to fix carbon (obtained from carbon dioxide) into the glucose. It is also called as biosynthetic phase.