Photosynthesis is the chemical process by which energy stored in light is converted into chemical energy stored in sugar. The prefix “photo” refers to the importance of light in the process. Photosynthesis is carried out by green plants using chlorophyll.
Photosynthesis takes place within chlorophyll-bearing cells. There are three inputs to the chemical reaction: water, carbon dioxide and light. In the natural world, the light source is the sun, although sufficiently strong artificial light will suffice.
The photosynthetic reaction converts the carbon, hydrogen and oxygen in water and carbon dioxide to sugar that is stored in the plant’s cells. The byproduct of photosynthesis is oxygen. Green plants remove carbon dioxide from the atmosphere during photosynthesis and release oxygen.
Light energy is an essential input to photosynthesis. The process cannot take place without sufficient light, so photosynthesis cannot take place at night except under artificial lights.