This book advances the knowledge of the mechanism development of a lived organism during its lifetime through the normal stationary state and quasi-stationary pathologic state from the viewpoints of biochemistry, biophysics, and thermodynamics. It explores the possibility of estimating experimental results from the three points of view, giving a broad perspective on the interaction between an organism and its environment. The book also describes the biophysical and biochemical mechanisms’ maintenance stability of internal energy according to the First and Second Law of Thermodynamics.