Question

Suppose there were plants that had a high concentration of chlorophyll b but lacked chlorophyll a. Would it carry out photosynthesis ? Then, why do plants have chlorophyll b and other accessory pigments ?

Answer 1

Chlorophyll a is essential for photosynthesis because only its special molecules function as reaction centres ($P_{700},P_{660}$). Reaction centres convert light energy into chemical or electron energy. Photosynthesis is, therefore, absent in plants lacking chlorophyll a.The importance of chlorophyll b and other accessory pigments is
(i) Absorption of light rays of different wavelengths and transfer of this enery to reaction centre through resonance, (ii) Protection of chlorophyll a reaction centre from nascent oxygen and other destructive radicals.