Excitation and electron transfer are important elementary processes in photosynthetic energy conversion. Recent developments in experimental techniques, such as laser photolysis and purification of protein complex from membrane systems, enable us to discuss these processes at the microscopic level.
This review summarizes the recent experimental and theoretical developments in this field and discusses the present problems and future prospects.
In particular, we discuss the following topics in detail: (1) The Theory of photosynthetic excitation transfer, and how it can explain the ultrafastness and high efficiency of this process. The temperature dependence of the excitation transfer and its correlation with these properties. (2) Nonlinear phenomena in the photosynthetic excitation transfer and their significance in understanding the topology of the photosynthetic unit. (3) The quantum-mechanics of photosynthetic electron transfer and its use to explain the temperature dependence of the transfer rate. Possible explanations of the ultrafastness, high efficiency and irreversibility of the primary electron transfers around the reaction center.