BAINES, A.T.; MCVEY, M; THOMPSON, J.T.*; WILKINS, H; University of North Carolina; University of North Carolina; University of North Carolina; University of North Carolina: The mystery of the toxic flea dip: an interactive approach to teaching aerobic cellular respiration
We designed a case study to teach aerobic cellular respiration to major and non-major introductory biology students. The case was designed originally for three 50-minute lecture periods but we have also modified it for a 3-hour class that meets only once per week. The case is based loosely on a real-life incident of rotenone poisoning. It places the students in the role of a coroner who must determine the cause of death of the victim. The case is presented to the students in four parts. Each part is followed by discussion questions that the students answer in small groups prior to a class-wide discussion. Successive parts of the case provide additional clues to the mystery and help the students focus on the physiological processes involved in aerobic respiration. Students learn the information required to solve the mystery by reading the course textbook and using interactive websites prior to class, through three (~20 minute) lectures interspersed throughout the case, and by discussing the case in small groups. We encourage reading and website use prior to class by giving the students a short quiz at the start of the second class. The three lectures focus on (1) energy and thermodynamics, (2) the relationship between thermodynamics and diffusion, active transport, and enzyme function, and (3) oxidative phosphorylation, electron carriers, and chemiosmosis. The case ends with small group discussions in which the students are given the names and specific molecular targets of other poisons of aerobic respiration and asked to determine which process (i.e., glycolysis, citric acid cycle, or the electron transport chain) the toxin disrupts.