Autotrophic Nutrition - Photosynthesis

Biology

Concept: Autotrophic Nutrition - Photosynthesis

Carbon and energy requirements of the autotrophic organism are

fulfilled by photosynthesis. It is the process by which autotrophs take

in substances from the outside and convert them into stored forms of

energy. This material is taken in the form of carbon dioxide and water

which is converted into carbohydrates in the presence of sunlight and

chlorophyll.

The excess of carbohydrate produced in plants is converted into starch and stored or transported throughout the plant body. In animals(human beings) the food which is not used is stored as glycogen, which gives rise to obesity. So, the next time you see a fat person, just remember, that he eats the same as you do, but he only does''nt use it as you do.

Raw materials required for Photosynthesis to occur:

• CO2
• Sunlight
• Water
• Chlorophyll

Steps involved in the process of photosynthesis:

• Absorption of light energy by chlorophyll.
• Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen.
• Reduction of carbon dioxide to carbohydrates.

The above steps when performed during the day, are called Light Reactions.

Desert plants take up carbon dioxide at night and prepare an intermediate which is acted upon

by the energy absorbed by the chlorophyll during the day. Such reactions are called Dark Reactions.

Summary of the above concept:-