The surface energy of water; molecular biology of the working mechanisms

The surface tension and surface energy of water, have been studied for two centuries. The ability to do physical chemical work dates from the decades at the close of the nineteenth century and opening of the twentieth. Teaching and research popularity dropped in the post-war years, and today is practically unique. Before 1846, Laplace, the French scientist, found that pressure was needed to force water, or other liquid, through small holes. The pressure needed was greater for smaller holes, and the relationship depended upon the surface tension of the liquid under test, and the inverse of the radius of the holes. The Laplace formula still appears in Physiological textbooks. The importance in the small air tubes of respiratory physiology, and in the capillary circulation generally, is still studied. The use of surface energy for protein conformational changes has received little attention. A proposed scheme for the human erythrocyte glucose transporter, although shown to be experimentally consistent, has been disregarded. A possible reason is the difficulty of comprehending how surface energy can actually perform mechanical work. Therefore, studies with molecular models, which increase the understanding of how mechanical work is done are described in more detail here.