A novel concept and, therefore, a novel discipline is defined, wherein molecules are described as frameworks of strategically located functional components within molecular structures, acting in unison to effect efficient energy management. The term "systems chemistry" effectively serves to define the phenomenon of an assembly of atoms and functional groups within a molecule having systemic properties "valued" at more than their component sum. The reduction of NAD(+) and FAD is complimented by an enthalpy transfer between organic functional components (aromatic ring, amide and olefinic functionalities), yet the sum of the overall energy values (the total system) remains nearly constant, irrespective of which direction the redox reaction proceeds. From this aspect, both NAD(+) and FAD operate as real chemical systems of atoms and functional groups, working together within the individual molecules to store the reaction enthalpy as resonance enthalpy, rather than manifesting it as emitted or absorbed heat. In this way, the thermoneutral reaction of the wet combustion occurring in all living cells is made possible by all internal "cooling process".