THE ROLE OF WATER IN BIOLOGICAL-SYSTEMS

A general model of the liquid water structure consistent with its physical, chemical, structural, and also biological properties has not been described in the literature so far. Therefore, different structure models of liquid water have been taken into account in relation to its OH stretching Raman modes. Some factors (structure factor, H-bond cooperativity) typical of liquid and biological water have been considered. Also, the different roles played by water in biological systems are elucidated and discussed by means of a few general structure models, suitable for explaining the perturbations induced on liquid water by solutes (ionic, acids and bases, apolar) and surfaces. In particular, the possibility of strong acid-base H-bond interactions between different groups has been explored together with the biological role of water. Furthermore, the modulating effect of water on the H-bond strength and the consequent properties have been hypothesized. Finally, the behaviour of water structure in tissues and its possible correlation with normal and pathological conditions are reported.