The book provides basic information about the mechanisms of energy conversion in living organisms. Systems of substrate, photo- and oxidative phosphorylation are considered, supplying all the energy necessary for the life of organisms. Ways of generating membrane forms of energy, as well as their use for ATP synthesis, accumulation of chemicals in cells and organelles, bacterial mobility, heat generation for thermoregulation, etc. are described. In conclusion, the ways of practical application of bioenergy to cancel the aging program of the body are considered. For undergraduate and graduate students of biological faculties of universities, as well as for specialists in the field of bioenergy, biochemistry, biophysics, pharmacology, physiology and microbiology.