Conceptual advances in organized solutions: a milestone in the physical chemistry of biological organization

Ideal dilute solutions, electrolyte solutions, regular solutions, regular polymer solutions and fused salts have been considered widely different systems. Yet an idealization of completely randommixingbythermal motion is adequate in these systems. In this respect these solutions are similar. Such recapition yielded a new concept, i.e., "Organized So lutions" . From the comparison of characteristic ?roperties of randomly mixed solutions and organized solutions , another new concept "Ideal Organized Solution" was evolved and further the conditions for the self-organization were derived. In idealized organized solution (system), such as lecithinwater, 1. random mixing region is negligibly small, 2. hydrated organized phase separation or organized aggregate formationoccurs above the saturation concentration of singly dispersed species, and 3. self-organization of solute molecules occurs due to the association of strong solvent-phobic groups and the orientation of solvent-philic groups to depress the Gibbs energy of the system. At the saturation concentration Gibbs energy decrease due to maximum 'disorder' and Gibbs energy increase due to the dispersion of solvent-phobic groups just balance. Biological organization has been considered at variance with the second law of thermodynamics. The quality factor by Manfred Eigen and the dissipative structures by Ilya Prigqine =re introduced in order to explain biological organization. In this paperr however, self-organization in amphiphile system was explained as a natural consequence of thermodynamics. Self-organization of proteins and lipids may be similarly understandable. INTRODUCTION Ideal dilute solutions, electrolyte solutions , regular solutions, regular polymer solutions and fused salts greatly differ from each other depending on the types of solvmts from hydrocarbon to water and on the nature of interactional forces from Coulombic to London dispersion. These solutions have been considered widely different systems. Yet an idealization of completely random mixing by thermal motion is adequate in these systems. In this respct these solutions are similar. Such recognition seems a meaningful concept itself and served to recognize organized systems (1). These random mixing solutions, however, represent exceptions among many cases which are encountered in the real world of m y biolqically and technologically important systems, such as amphiphile systems, lyotropic liquid crystals, solubilized solutions, functional polymer solutions, biological systems, etc. Randomly mixed solutions and organized solutions are summarized in TABLE 1. TABLE 1 Disorganized and Organized Solutions. Disorganized solutions Organized solutions (Randomly mixed solution) (Dilute random mixing solution + Organized phase or particles) Ideal dilute solutions Amphiphile solutions(systems) Electrolyte solutions Vesicles, Liposomes Regular solutions Lyotropic Liquid Crystals Regular polmer solutions Solubilized solutions Fused salts Amphipathic polymer solutions (Protein solutions) Inorganic, Unnatural Biological, Functional, Natural