Why does the rate of photosynthesis decrease at higher light intensities? What plays a protective role in such situations?
Rate of photosynthesis decreases for two reasons : (i) Other factors required for photosynthesis become limiting. (ii) Destruction of chlorophyll by photo-oxidation. Carotenoids play a protective role by: (i) absorbing the excess light and (ii) acting as an antioxidant to detoxify the effect of activated oxygen species.
