ABSTRACT
In addition to gravity, light is one of the most important external factors, not only for photosynthetic organisms,to control their movement and position in their habitat.For photosynthetic bacteria,algae, and higher plants,solar radiation is an indispensable source of energy.During evolution,a number of light-harvesting pigments have been developed for collecting solar energy,most of which are based on cyclic tetrapyrroles.In addition,a number of di¨erent accessory pigments are being utilized to augment the amount of light absorbed by funneling the energy to the reaction centers for photosynthesis.
