Question

In which stage of photosynthesis light is directly necessary?

Answer 1

Photosynthesis is a process used by plants and other organisms which converts light energy to chemical energy with the help of chloroplast. The formed chemical energy is stored in the form of carbohydrate molecules which are synthesized by carbon dioxide and water and the released by product is oxygen.

Complete answer:
Process used by plants and other organisms which converts light energy to chemical energy with the help of chloroplast is known as photosynthesis. These organisms are known as autotrophs because they can prepare their own food with the help of light energy.

They are also known as the primary producers as they are first one in the food chain because of their ability to do photosynthesis. Oxygen is released as the by-product which is essential for the survival of organisms.

Plants, algae and cyanobacteria which perform photosynthesis are also known as photoautotrophs. The process always begins when the light energy is absorbed by reaction centres which are basically a form of protein which contains the chlorophyll molecule. In plants these proteins are held by chloroplasts which are most abundant in leaf cells.

There are two types of reaction in photosynthesis:
Light reaction (Light dependent reaction)
Dark reaction (Light independent reaction)

For the initial stage (That is light reaction (Light dependent reaction)) of photosynthesis, direct light is necessary. This absorbed light energy excites the electron which later follows cyclic or non cyclic pathways in cyclic phosphorylation.

Note:
Photosynthesis is a process used by plants and other organisms which converts light energy to chemical energy with the help of chloroplast. For the initial stage of photosynthesis, direct light is necessary. This absorbed light energy excites the electron which later follows cyclic or non cyclic pathways in cyclic phosphorylation.