This article presents a teaching methodology for free radical theory and discusses the role of antioxidants in human health. Free radicals are a normal byproduct of respiration, which allows the body to use oxygen, liberate energy, and dispose of harmful substances. The body's antioxidants and nutritional antioxidants quench most of the free radicals produced. Free radicals drain the body's molecular system of energy by stealing energy in the form of electrons, a process which manifests itself in aging. Growing evidence indicates that this process can be prevented or delayed by dietary changes, such as reduction in fat intake and increased consumption of fruits, grains, and vegetables as well as increased intake of dietary antioxidants, such as vitamin E. Teaching about antioxidant nutrients can be enhanced by renting a cartoon video with a scene from the television cartoon "Mighty Mouse" and showing the class a scene where Mighty Mouse transforms into a super-mouse by consuming nutrients/vitamins and asking appropriate questions. Other effective teaching techniques include showing a transparency on the levels of organization in nature or on a simplified model of atomic structure; explaining the dangers of free radicals to students; asking students to list the fruits and vegetables recently consumed and focusing on including more of these in their diet; and explaining the benefits of eating fresh fruits and vegetables to students. (Contains 21 references.) (CK)