This book presents a complete review of biological energetics and responds systematically that there is no possible activity without bio-energy in the living bodies. In this case, we elucidate and describe concretely the generations of bio-energy and its properties, regulation of bio-energy metabolism, bio-energy transport and its theoretical description, the stability of bio-energy transport, the experimental evidences of correctness of bio-energy theory and its wide applications, as well as the use of bio-energy in living systems involving animals, plants and human beings. Additionally, the biological phenomena, processes and effects related to bio-energy are also delineated, explained and shed light on theoretical calculations and analyses, numerical simulations and experimental measurements using biology, molecular biology and biophysics. This book contains seven chapters, in which 380 pages and a great number of illustrations and figures reveal the theoretical and experimental results. It is intended for researchers, teachers, graduate students and upper-level undergraduate students.