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A Diet to Die For

An Exploration of Oxidative Phosphorylation


Terry Platt
Department of Biology
University of Rochester
Eric Ribbens
Department of Biological Sciences
Western Illinois University


This clicker case is designed to lead students to a conceptual understanding of oxidative phosphorylation (and, by analogy, photosynthesis). Students begin with a pre-class handout that presents background information on DNP, a weight-loss drug that was used in the 1930s, often with fatal consequences, leading to the establishment of the Food and Drug Administration. In the classroom, students work through a PowerPoint presentation about a college athlete who uses dinitrophenol obtained on the internet to lose weight, and winds up in the emergency room. Investigation by his twin sister reveals the scientific reasons for the dangers he encountered. The same topic with a slightly different emphasis is presented in another case in our collection titled "Wrestling with Weight Loss: The Dangers of a Weight-Loss Drug."


  • Instill a historical appreciation for DNP's early use as a weight loss drug and its role in the formation of the Food and Drug Administration as a regulatory agency.
  • Use current issues of dieting and weight loss via internet drugs to engage student interest in the toxic effects of DNP.
  • Challenge students to think about how inhibition and uncoupling effects of drugs can deepen their understanding of oxidative phosphorylation in eukaryotic systems.
  • Encourage students' curiosity as to the chemical reasons for DNP toxicity in the context of the chemiosmotic hypothesis.
  • Stimulate interest in further study by showing how biological control of oxidative phosphorylation can generate warmth in human babies, for example.
  • Promote an overall understanding of the relationship between ATP synthesis via oxidative phosphorylation and electron transport in eukaryotic cells.


Dinitrophenol; DNP; electron transport; oxidative phosphorylation; ATP synthesis; uncoupler; uncoupling; mitochondria; dieting drug; chemiosmotic theory; Peter Mitchell; substance use

Topical Areas

Ethics, History of science, Scientific method

Educational Level

Undergraduate lower division


PDF, PowerPoint

Type / Methods

Clicker, Interrupted



Subject Headings

Biology (General)  |   Biochemistry  |   Cell Biology  |   Public Health  |   Pharmacy / Pharmacology  |  

Date Posted


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