New concepts of chemical and biological structure: Consequences of consistently treating weak bonds as chemical structural determinants

Abstract

It is currently held that biological systems are structural hierarchies composed of increasingly smaller units at each more precise level of resolution. Within this hierarchy, the molecule is the unit of chemical structure. Extensive observation shows that weak chemical bonds like hydrogen bonds, van der Waals forces and weak electrostatic forces are widespread and significant determinants of the properties of biological systems. At present, these weak bonds are inconsistently taken into account in describing the chemical structure of biological systems. I propose that weak chemical bonds be systematically treated as chemical structural determinants. Two important consequences follow. First, the molecule is no longer the unit of chemical structure in biological systems; in its place we obtain a large complex unit whose boundaries at any given instant encompass all the atoms we customarily think of as those of an organism. Second, as a result of the size of this unit and the disposition of its boundaries, an organism can no longer be held to consist of a hierarchy of structural units each with its own boundaries which exist independent of our method of observing them. In this new view, the impression that there are discrete boundaries to each of the several units of the hierarchy such as molecules and cells, is seen to result from the measurement error inherent in the level of resolution at which the boundaries of each of these units is observed.