Photosynthesis is a phenomenon which is responsible for life on earth.
It occurs in the green parts of plants especially in the leaves.
Even in smaller organisms like blue green algae, bacteria and protozoa also photosynthesis occurs .
This enables these organism to make their own food material without requirement to depend on others.
Hence, plants are the prime source of food in the food chains.
But how does photosynthesis work?
Photosynthesis work based on 3 factors
2. Chlorophyll or similar green colored pigment
3. Carbon dioxide and water.
The general formula for photosynthesis is as
Carbon dioxide reacts with water in presence of light energy. The light energy needed for this reaction is absorbed in the chloroplasts of the plant cells.
The light has energy in the form of ATP and is trapped in the form of chemical bonds inside the carbohydrate molecules. Besides, oxygen is also released, hence it is beneficial in either ways of life for animals.
So based on the above discussion, photosynthesis works only in the presence of
Light: Light can be either the sunlight or even from the electric bulb. This means plants can perform photosynthesis even in night if there is light from electric source.
Chlorophyll: This is the pigment present in plant cell organelle namely chloroplasts. Chloroplasts are high in number in the cells of the leaves of plants. Hence, if you notice, leaves tend to bend towards light. In the evenings, they droop as there is no light. This behavior of leaves is an attempt to trap sufficient light energy required for photo synthesis.
This is a green pigment which has the ability to trap light energy. This trapped light energy is used to run photosynthesis reaction.
Carbon-dioxide: Water is always available to plant from ground. Water is also necessary for the plant for transport of sap within the body. It is also needed to remove heat from the plant by transpiration.
But carbon-dioxide is needed only for photosynthesis. It is available from the atmosphere. Even during respiration, plants release some amount of carbon-dioxide. So carbon dioxide is also mostly available. Both water and carbon dioxide form the carbohydrate completing the photosynthesis process.