Figure 2 Structures of surfactants and lipids that form bilayers.

Myoglobin is a muscle protein (molecular weight about 17,000) that contains an electroactive iron heme prosthetic group. It is a good model protein for voltammetric studies in films because its crystal structure is known to high precision, pK values of all of its amino acid side chains have been measured, and its solution electrochemistry is slow under ordinary solution conditions. Although it is an oxygen storage and transport protein, it can be made to act like an enzyme [11].