Photosynthesis was named as such because it uses light as a source of energy for the chemical reactions it needs. Plants get that energy from the sun in the form of light and use it to create the substances they need to survive. Without light to provide the energy for the reactions, the plants can’t make the food that they need to stay alive.
Light provides energy for the synthesis of glucose from carbon dioxide and water during photosynthesis.
During light reaction, the chlorophyll entraps light and the solar energy is converted into chemical energy in the form of ATP molecules. This can happen because light energy is used to split water