What do plants need in order to perform photosynthesis?

What do plants need in order to perform photosynthesis? They need sunlight. Light supplies the energy that plants use to turn water and carbon dioxide into chemical energy stored in sugars.

Photosynthesis mainly takes place in chloroplasts, tiny structures inside plant cells. The green pigment chlorophyll absorbs light, especially red and blue wavelengths, while reflecting much of the green light that makes leaves appear green. Water enters primarily through the roots, and carbon dioxide enters through tiny openings in leaves called stomata.

During the light-dependent stage, light energy helps split water molecules, releasing oxygen. In the Calvin cycle, the plant uses captured energy to incorporate carbon dioxide into carbohydrates such as glucose. Plants later use those sugars for growth, repair, and cellular respiration.

Sunlight is essential, but it is not the only requirement. Photosynthesis also depends on water, carbon dioxide, suitable temperatures, and functioning chloroplasts. Jan Ingenhousz showed in 1779 that light was crucial to plants’ ability to restore oxygen to the air.