Question

What is a photosystem?

Answer 1

A photosystem is a complex in which photosynthetic pigments are arranged in the form of clusters for the efficient absorption and utilization of sunlight energy in thylakoid membranes.

Explanation:

Photosystem constitutes two main parts. A brief concept to them is as follows:

• Antenna Complex:
  It is a light- harvesting complex containing proteins and many molecules of `"cholorophyll a"`, `"cholorophyll b"` and `"carotenoids"`. Photons of light are first absorbed by antenna complex pigments which then transfer the energy to the reaction center.
• Reaction Center:
  It has one or more molecules of `"cholorophyll a"` along with primary electron acceptor and associated electron carriers of electron transport system.
  It receives the absorbed sunlight energy from the antenna complex and convert that energy into `"chemical energy"`.

`Note:`

In plants and photosynthetic green algae `to` photosystem are present in thylakoid membranes of choloroplast.

In photosynthetic bacteria `to` photosystem are present in plasma membranes.

Hope it helps...