Forces Across Membranes
Much of the chemistry and functional physiology of the cell, including energy production, protein synthesis, hormone and antigen binding, stimulus–response coupling, and nutrient adsorption, occurs at the cell membrane. The membrane is an anisotropic non-homogeneous matrix of lipids, proteins, and, in some cases, carbohydrates that is in intimate contact with aqueous-dominated interphases. The nature and treatment of aqueous solutions, membrane properties, and interphase structure have all been presented in previous chapters. The task ahead is to highlight this knowledge by examining some limited aspects of the behavior or action of biochemical systems. In this chapter we focus on describing the forces operating at and across the membrane. Then we will examine the role of the membrane in modulating the flow of materials.