Explain the mechanism of absorption of light by chlorophyll.

Explanation

Chlorophyll a absorbs a photon of certain wave length in the visible light of red-blue region (680 nm-700 nm). The energy of photon is transferred to electron in the chlorophyll molecule. This electron goes to excited state and is transferred to electron acceptors in the thylakoids. After a series of complicated reactions, it reaches the water molecule. Thus the chlorophyll molecule gets oxidized. Water undergoes photolysis producing oxygen molecules which are difused out. The `H^(+)` ions and electrons are used to reduce the NADP and the energy so transferred gets stored in ATP molecules. The electrons again reach the chlorophyll which gets reduced and comes to normal state.