Why is chlorophyll-a called an essential pigment?

Explanation

Chlorophyll-a is a called an essential pigment for the following reasons:
1. Chlorophyl-a absorbs and utilizes the light energy for photo-chemical reaction.
2. Chlorophyll-a,converts the light energy into chemical energy i.e., ATP which is necessary for the variou slife activities of auto-trophic organisms. The accessorypigments trp the solar energy and pass it on to the chlorophyll-a which converts it into ATP.
4. Chlorophyll-a is responsible for the photolysis of water and the release of oxygen. Oxygen thus released is necessary for the sustenance of life.