How carotenoids function in photosynthetic bacteria.

Carotenoids are essential for the survival of photosynthetic organisms. They function as light-harvesting molecules and provide photoprotection. In this review, the molecular features which determine the efficiencies of the various photophysical and photochemical processes of carotenoids are discussed. The behavior of carotenoids in photosynthetic bacterial reaction centers and light-harvesting complexes is correlated with data from experiments carried out on carotenoids and model systems in vitro. The status of the carotenoid structural determinations in vivo is reviewed.