Explain the importance of accessory pigments in photosynthesis.

Accessory pigments, such as carotenoids and xanthrophylls, increase the rate of photosynthesis by increasing the efficiency of light absorption in both photosystem I and II, specifically in the light harvesting complexes. This is because accessory pigments absorb different wavelengths of light compared to chlorophyll a molecules, and then transmit this energy to the chlorophyll a molecules in the reaction centre. This allows a larger range of photons to be absorbed, as well as more in general due to the larger area covered by the accessory pigments.Carotene, a type of carotenoid, also has a secondary role of protecting the chloroplast against reactive oxygen species produced during photosynthesis.