Hello! Socratic's Terms of Service and Privacy Policy have been updated, which will be automatically effective on October 6, 2018. Please contact hello@socratic.com with any questions.

What is a photosystem?

1 Answer
Dec 26, 2017


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.


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"#.



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...