Carotenoid-sensitized photosynthesis: Quantum efficiency, fluorescence and energy transfer

The observation in the early 1940s that the quantum efficiency of photosynthesis in a diatom was almost the same whether incident light was absorbed by chlorophyll a or by fucoxanthol sparked subsequent investigations of the variety of chloroplast pigments and in a diversity of photosynthetic organisms. Subsequent fluorimetric measurements provided the first relevant observation on the existence of excitation energy transfer in photosynthesis. These and some other experiments prior to the classical work of Arnold and Oppenheimer [(1950) J Gen Physiol 33:423-435] and of Duysens [(1952) Doctoral thesis, State University of Utrecht, the Netherlands] are reviewed here.