Thermodynamical Analysis of Life III. Mathematical Analysis of Metabolism

Abstract

Living organism is the open system, in which chemical substances are taken from the external system and excreted. Let the free energy taken and excreted be Z₁ and Z₂ respectively, then the change of the free energy of the organism is
\dotG_k=Z₁−Z₂−D, (4.5)
where D is the free energy used to maintain life or for external work W. G_a be the free energy of the external system, then −\dotG_a=Z₁−Z₂ and the second law may by written in the form
\dotG_a+\dotG_k=−D<0. (4.8)
On the other hand \dotG_k can be written in the form
\dotG_k=R−D_r, (5.7)
where
R=Z₁−Z₂−W−D_f,D_r=D−W−D_f (5.6)
and D_f is the energy loss in our body. This is the fundamental equation of thermodynamics of life. R is the repair of free energy of the organism and D_r is its depreciation.