Photosynthesis is the process by which green plants use light energy to make their own food. Chlorophyll in the plant cells traps light energy, then carries out a series of reactions.
Plants carry out photosynthesis to make their food. Oxygen is produced and released as a by-product of photosynthesis. Light energy from the sun is absorbed by a green pigment called chlorophyll and used to make sugars, which store chemical energy.