In the models of prebiotic processes, flavins and other pteridine derivatives transform light energy into the energy of chemical bonds, including energy-rich bonds of ATP. In the course of biological evolution, these compounds have not lost photoreceptor function, which is preserved in photoenzymes and photosensory proteins responsible for adaptation of organisms to environment. A set of data suggests that, in the early evolution, there was a possibility of the formation of flavin converter of light energy, which is a functional prototype of photosynthesis.