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-Core molecules, B-Antenna molecule, C-P680, D-primary e acceptor
B. A-Antenna molecules, B-Core, C-P700, D-Primary e acceptor
C. A-Antenna molecules, B-Core, C-P700, D-Plastocyanin
D. A-Core molecules, B-Reaction centre, C-P680, D-Plastocyanin

Answer 1

Hint: The LHC or light-harvesting complex is an antenna complex is a series of proteins and chlorophyll which are present inside the thylakoid membrane of plants and cyanobacteria. It transfers light energy chlorophyll molecules at the reaction station in the photosystem.

Complete answer:
The light harvesting complex is the major complex whose function is to collect light and transfer the energy to the reaction centres or the photosystems for the redox process where it gets converted into chemical energy.

The Light harvesting complex has the following parts-
- Core complex-It contains 40-60 chlorophyll molecules.
- Antenna complex- It contains many pigments which absorb various wavelengths of light and transfer the absorbed energy to the core complex which is finally transmitted to the reaction centre.
- The reaction centre is the chlorophyll molecule which is P700 which absorbs light of wavelength 700. It is the primary donor present in plants, algae or cyanobacteria.
- The valence electron released is excited to the higher level which is absorbed by the primary electron acceptor.

Hence the correct answer is B.

Note: The pigments used in the light harvesting complex are the water-soluble pigments which are attached to open-chain tetrapyrrole which is obtained from heme. The pigment proteins are made of phycoerythrin, phycocyanin and allophycocyanin. Its role is to harvest light energy.