Demonstrating the steps of a signal transduction cascade usually involves radioactive materials and thus precludes its use in undergraduate teaching labs. Developing labs that allow the visual demonstration of these steps without the use of radioactivity is important for allowing students hands-on methods of illustrating each step of a signal transduction pathway. One such pathway is the calcium/calmodulin signal transduction pathway. In this article, the author presents an enzyme activation demonstration that he has used in his undergraduate class. The author's presentation used simple supplies and inexpensive reagents. (Contains 2 figures.)