Comprehensive Biochemisty, Volume 27: Photobiology, Ionizing Radiations deals with the aspects of bioenergetics, immunochemistry, photobiology, and molecular phenomena that underlie the evolution of organisms. This book discusses the types of phototropic response, action spectra in the further ultraviolet, and structure and light-absorbing properties of the photoreceptor cells. The preliminary remarks on visual pigment structure, synopsis of extracted systems, oxidation of proteins, and effects of ultraviolet radiation and photoreactivation are also elaborated. This text likewise covers the chemical nature of photoreactivable damage, reversibility of potentiated flowering response, and primary reactions in algae and higher plants. This volume is beneficial to biochemists and specialists researching on ionizing radiations.