Photosynthesis - Process, Required Raw Materials and Products

Green plants can manufacture their own food. They prepare food not only for themselves. The food is utilized by all animals and plants which cannot manufacture their own food. Green plants contain chlorophyll which is green pigment. Chlorophyll can trap sunlight. Green plants prepare food with the help of raw materials like carbon dioxide (CO₂) and water (H₂O) in the presence of sunlight. The food prepared by the plants is stored in the
form of sugar and starch in different parts. The process of making food by green plants using carbon dioxide and water in the presence of sunlight and chlorophyll is known as photosynthesis. The photosynthesis process can be written in brief as:

6CO₂ + 6H₂O ---------^{light or chlorophyll} ---------> C₆H₁₂O₆ + 6O₂

Raw Materials Essential for Photosynthesis

a) Carbon dioxide (CO₂): The source of carbon dioxide is atmosphere for all the terrestrial plants whereas aquatic plants use dissolved CO₂  from water. Carbon dioxide is released by the plants and animals to the atmosphere by their respiration process. The other sources from carbon dioxide in the atmosphere are combustion of coal, fossil fuel and natural gases.

b) Water  (H₂O): Water is one of the raw material for photosynthesis. Plants absorb water and dissolved materials from soil with the help of roots. Then, water is transported to different parts of the plant such as stem, leaves through conducting tissues.

c) Chlorophyll: Chlorophyll is the green pigment present in green parts of the plant mostly in the leaves. They are contained inside chloroplast which helps in photosynthesis. When sunlight falls in the chlorophyll, photolysis of water takes place liberating electrons which help in forming ATP (Adenosine Triphosphate).

d) Light: Light energy is one of the most essential raw materials to carry out photosynthesis process. Sun is the source of light energy.

Products of Photosynthesis

The major products of photosynthesis are oxygen and sugar. Oxygen thus liberated balance the atmospheric oxygen which is continuously consumed by the plants and animals during respiration. Sugar produced during photosynthesis is used by plants to synthesize organic compounds like carbohydrate, organic acids, proteins, fats, hormones, vitamins, alkaloids, etc.