Photosynthesis is a process by which plants and other organisms utilize light energy absorbed from the Sun to convert carbon dioxide and water into simple sugars like glucose. In Greek, “phos” means light and “synthesis” means putting together.

It takes place within specialized cell structures called chloroplasts which contain green pigments called chlorophyll. Photosynthesis occurs in two stages. In the first stage, which is a light dependent reaction, the chloroplasts are involved in trapping light energy and converting into chemical energy. The end products of this reaction are NADPH and ATP, which are required for the second stage of the reaction. In the second stage, which is the light independent reaction (dark reaction), NADPH provides hydrogen atoms that helps in the formation of glucose using energy from the hydrolysis of ATP.  The overall reaction for the process is

6CO₂       +         6H₂O     +        Light     ®      C₆H₁₂O₆      +          6O₂

Carbon dioxide  Water                                        Glucose                Oxygen