The process of making food in the leaves with the help of water and carbon dioxide in the presence of sunlight and chlorophyll is called photosynthesis.

In photosynthesis solar energy is converted into chemical energy.

Carbohydrate is formed in photosynthesis.

The significance of photosynthesis are:

  1. It is the important source of energy for all living organisms- both producers and consumers. It is essential for sustaining life.
  2. It helps in the growth and development of plants.
  3. It is necessary for the synthesis of many organic compounds used by man and other animals.
  4. It converts atmospheric CO2 back to oxygen.

The main source of carbon dioxide gas is the atmosphere, which consists 0.03% to 0.04% of the atmosphere. Water plants take CO2 dissolved in water. During respiration, CO2 is released by animals and plants. Plants are capable of utilizing this CO2, in addition to atmospheric CO2 for the purpose of making their food. During daytime, when light is available, plants fix the CO2 in photosynthesis.

Light is very important for photosynthesis. In photosynthesis, the light energy changed into potential chemical energy. Sun is the only main natural source of light energy. Artificial light is also effective in photosynthesis, but this light should be intensive. Only green plants are capable of utilizing this light energy.

The rate of photosynthesis is affected both by quality as well as the quantity of light. In the red color of light, the rate of photosynthesis is maximum and in light of green color, there is no photosynthesis. In this way, light is essential for photosynthesis.