Photosynthesis is the process by which green plants trap solar energy and convert it into chemical energy by carbohydrates. This process is unique to green plants. It is a complex series of reactions driven by light energy absorbed by chlorophyll and other pigments resulting in synthesis of organic compounds from carbon dioxide and water. Oxygen is produced as photosynthetic byproduct. Photosynthesis is only natural process by which oxygen is liberated into atmosphere.
The complete process of photosynthesis can be summarized as follows:
6 CO2 + 12 H2O + photons → C6H12O6 + 6 O2 + 6 H2O
Life on the earth depends upon photosynthesis directly or indirectly. Autotrophic organisms trap solar energy and convert it into food or any other form of energy by the process of photosynthesis. Approximately 0.2% of solar energy falling on the earth, which is utilized by the photosynthetic organism. This small amount of energy is utilized by the photosynthetic organisms which fulfills requirement of all the other heterotrophs.
Many plant products such as fibers ,timbers, resins, drugs etc. are produced by the process of photosynthesis.Photsynthetic plants produced petroleum products such as coal, natural gas, etc. which got buried long years back under the rocks. These plant products are very important energy source.
The most important role of photosynthesis is that it is the only process which adds oxygen to the atmosphere which is being utilized during the process of respiration by all living organisms. In this way photosynthesis balances the amount of oxygen and carbon dioxide in the atmosphere.