Wrestling with Weight Loss

The Dangers of a Weight-Loss Drug

Co Authors:	Susan M. DeSimone Biology Department Middlebury College sdesimon@middlebury.edu Annie Prud’homme Genereux Life Sciences Quest University Canada apg@questu.ca
Abstract:	In this interrupted case study, a young wrestler considers purchasing 2,4-dinitrophenol (DNP) online as a means to drop weight quickly. However, a finding that it may have killed someone concerns him. Through progressive disclosure of information, students expand their understanding of membrane permeability and the proton motive force in mitochondria to understand how DNP acts in mitochondria and how it may lead to various physiological effects. Follow-up assignments use knowledge gained in the case to understand mitochondrial thermogenesis in brown fat function and human evolution. The case may be used as a stand-alone exercise in a classroom or be paired with a laboratory investigation using isolated plant mitochondria. It is suitable for an introductory cell biology course for biology majors and non-majors.
Objectives:	Know the order and linkage of the biochemical processes involved in ATP synthesis in mitochondria (glycolysis, TCA cycle, electron transport chain, proton pumping, ATP synthase activity) Be able to describe how mitochondria may generate heat to maintain body temperature. Apply concepts underlying mitochondrial function to the mechanism of action of a specific diet pill. Be able to extract data from a graph, and use that data to make inferences about the action of DNP. Relate fundamental principles of mitochondrial function to their own health.
Keywords:	DNP; 2,4–dinitrophenol; mitochondria; mitochondrion; permeability; proton motive force; proton gradient; energy transfer; ATP; uncoupler; substance use
Topical Area:	N/A
Educational Level:	Undergraduate upper division
Formats:	PDF, PowerPoint
Type/Method:	Dilemma/Decision, Discussion, Interrupted, Laboratory
Language:	English
Subject Headings:	Cell Biology Molecular Biology Biology (General)
Date Posted:	1/19/2011
Date Modified:	N/A
Copyright:	Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

Teaching Notes

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Answer Key

Answer keys provide answers to the questions posed in a case study. Since these questions are intended to be answered by students and are often graded, answer keys are password-protected and access to them is limited to registered instructors.

Supplemental Materials

The case includes a set of three PowerPoint slides with animations of the diagrams given to students. They are intended to be shown in class between Parts II and III and Parts III and IV of the case.

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Excellent! I will use this in next week's tutorial. An imaginative way to convey an often dry subject. Thanks!

Terence Morris
Basic Health Sciences
BTIC
Ottawa
Terence_Morris@bcit.ca
1/19/2011

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