Explain the construction of the $LHC$ (Light Harvesting Complex) with a diagram.

- Each photosystem consists of all the pigments (except one molecule of chlorophyll-$a$) forming a light-harvesting system,also called antennae.
- These pigments help to make photosynthesis more efficient by absorbing different wavelengths of light.
- The single chlorophyll-$a$ molecule forms the reaction centre.
- In $PS-I$,the reaction centre of chlorophyll-$a$ has an absorption peak at $700 \ nm$,hence it is called $P_{700}$.
- In $PS-II$,it has an absorption maximum at $680 \ nm$,and is called $P_{680}$.