ABSTRACT
The macromolecules of life inhabit a watery medium. The charge state of DNA and proteins is largely controlled by the ionic character of the surrounding solution. Lipid molecules form ordered bilayers as a result of the unfavorable interactions of their tails with water. All life on Earth depends on water. Denial of water to cells and organisms rapidly leads to death. It has been said that more is known about our nearby celestial neighbors than about our own mysterious oceans. These giant liquid reservoirs have been the scene for some of life’s greatest evolutionary stories ranging from the tiny world of microbes and their viruses to the majestic whales that are the largest animals on the planet. Many events in the lives of biological molecules involve specific recognition of one molecule by another. The use of measured equilibrium constants can take people a long way toward understanding the charge state of macromolecules in solution.
