Antenna systems are highly regulated to maximize energy collection efficiency while avoiding photodamage. Some areas that are presently not well understood are listed. Introduction Nature's most sophisticated and important solar energy storage system is found in photosynthetic organisms, including plants, algae and a variety of types of bacteria. All these organisms utilize sunlight to power cellular processes and ultimately derive most or all of their biomass through chemical reactions driven by light. In this short report I will give an introduction to the basic principles of how natural photosynthetic systems work, including structural, mechanistic and regulatory aspects.
Photosynthesis begins when light is absorbed by an antenna pigment.
Antennas permit an organism to increase greatly the absorption cross section for light without having to build an entire reaction center and associated electron transfer system for each pigment, which would be very costly in terms of cellular resources. More details of antenna structure and function are given below. After the initial electron transfer event, a series of electron transfer reactions takes place that eventually stabilizes the stored energy in forms that can be used by the cell. In these organisms, the eventual electron donor is water, liberating molecular oxygen, and the ultimate electron acceptor is carbon dioxide, which is reduced to sugars. Other types of photosynthetic organisms contain only a single photosystem, which in some cases is more similar to photosystem 2 and in other cases to photosystem 1 of the oxygen-evolving organisms.