It is the process of synthesis of food by green plants in presence of sunlight. This is the only process by which solar energy is trapped in food molecules and during the process oxygen is also evolved. The survival of all types of organisms depends upon this process only.
It is the most important anabolic process by which green plants synthesize complex carbohydrates from simple substances like carbon dioxide and water with the help of light energy and purify the atmosphere by consuming CO₂ and evolving O2.
The overall equation usually given to represent photosynthesis is as under-
Importance of Photosynthesis:
Photosynthesis is considered the most important process because of the following reasons-
- Photosynthesis helps in the conversion of solar energy into organic matter that makes the bulk of the dry matter of any organism.
- It releases oxygen in the atmosphere. This oxygen is helpful for efficient utilization of the energy-rich molecules (carbohydrates) through respiration and in making ozone in the outer layer of the atmosphere.
- The agricultural productivity is also totally dependent on photosynthesis.
- Coal, petroleum, and natural gas have been formed inside the earth through the action of heat and pressure over organic matter which got buried due to various changes in the crust of the earth. Organic matter was a product of photosynthesis.
- Photosynthesis keeps the concentration of carbon dioxide nearly constant. Carbon dioxide is being added to the environment due to combustion and respiration. Plants regularly absorb carbon dioxide for performing photosynthesis. Therefore, one of the methods of checking the rise in atmospheric CO₂ concentration is to grow more plants.