The Electrified Interface

Abstract

Whereas homogeneous systems are relatively easily to describe, cellular processes are heterogeneous and more difficult to characterize. Because so many processes occur that require the exchange of components across at least one phase, it is extremely valuable for the biological scientist to have an understanding of the forces and structures that act in the zone of transition between phases. When different phases come in contact with each other, an interface between them occurs. This interface is a surface, and the properties of a surface are different from those of either of the phases responsible for creating it. In addition, the changeover between phases is never instantaneously abrupt; instead, there is a zone of transition extending from the surface for a finite distance into the bulk of each of the phases where the properties are representative of neither bulk phase. The surface and regions immediately adjacent are termed the interphase, a very useful distinction. The properties of interphases will be the subsequent focus of this section.