This module is concerned with biological macromolecules and complexes or arrays of macromolecules. The contents deal with conveying the major principles and concepts that are at the heart of the field. These principles and concepts are derived from physics, chemistry, and biology. The various topics to be discussed will cover some of the techniques used in studying structure and function of biological macromolecules, excitable cell membranes and ion channel activities. The emphasis is on a detailed discussion of a few techniques rather than an attempt to describe every known technique.