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The Mermaid and the Globins

Hemoglobin Function and Regulation


Nathaniel R. Beres
Department of Chemistry and Biochemistry
Heidelberg University


The function and regulation of hemoglobin is often difficult for students to understand. This directed case study is an attempt to make the topic more approachable by relating the story of “Joanna” and “Alex,” two students who visit their local aquarium to watch a sea lion show featuring a skin diver costumed as a mermaid. Impressed by the fact that sea lions and skin divers can hold their breath so long, Joanna and Alex engage in conversations with the mermaid, an aquarium trainer and their teaching assistant to learn about the function of myoglobin and hemoglobin as well as the regulation of hemoglobin. They also learn about allosteric modifiers of hemoglobin. This activity was developed for a general or advanced undergraduate biochemistry course, but it could easily be adapted for use in a human physiology or comparative physiology course. Prior to running the case in class it would be useful, although not necessary, for students to have some knowledge of protein function, basic chemistry (including equilibrium and pH), and hemoglobin.

  • Outline the function of myoglobin and hemoglobin in the human body.
  • Discuss some challenges/benefits of free-diving involving oxygen regulation.
  • Describe how the conformations of hemoglobin impact oxygen affinity.
  • Describe how H+, CO2, and 2,3-BPG affect the oxygen affinity of hemoglobin.
  • Provide a basic explanation of cooperative binding.
Keywords: Hemoglobin; myoglobin; oxygen; binding-curve; cooperative binding; fractional saturation; allosteric regulators; 2,3-BPG; skin divers; mermaids; sea lions; holding breath
Topical Area: N/A
Educational Level: Undergraduate lower division, Undergraduate upper division
Formats: PDF
Type/Method: Directed
Language: English
Subject Headings: Biochemistry   Physiology  
Date Posted: 10/11/2018
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.

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