Question

Given figure depicts the light harvesting complex (LHC) of photosystem I (PSI).
Select the correct identification for A, B, C and D

• A. A-molecules; B- Antenna molecule; C- $P_{680}$; D- Primary $e^{-}$ acceptor.
• B. A-Antenna molecules; B-Core molecule; $P_{700}$; D-Primary $e^{-}$ acceptor.
• C. A-Antenna molecules; B-Core molecule; $P_{700}$; D- Plastocyanin
• D. A-Core molecules; B- Reaction centre; $P_{680}$ ; D-Plastocyanin

Answer 1

The correct option is B A-Antenna molecules; B-Core molecule; $P_{700}$; D-Primary $e^{-}$ acceptor.

Each pigment-protein complex consists of a core complex( having a reaction centre plus about 40- 60 chlorophyll molecules) and an antenna complex. Various pigment molecules in the antenna complex absorb different wavelengths of light and transfer their absorbed energy to the core complex which is finally concentrated in the reaction centre- chlorophyll. The later takes part in the photochemical reaction. The outer valence electron gets excited to a higher energy level which is captured by the primary electron acceptor.

So, the correct answer is 'A-Antenna molecules;B- core molecule; P${}_{700}$; D- Primary e${}^{-}$ acceptor'.