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Caught Red-Handed

Hemoglobin, Carbon Monoxide, and a Butcher’s Knife


Mackenzie A. Hahn
School of Nursing
Texas Tech University Health Sciences Center
Hannah C. Schake
Kinesiology and Sport Management
Texas Tech University
Ryan T. Schalles
School of Nursing
Texas Tech University Health Sciences Center
Sarah R. Shioji
School of Nursing
Texas Tech University Health Sciences Center at Abilene
Breanna N. Harris
Biological Sciences
Texas Tech University


Was the "Brooklyn Butcher" of 1926 a cold-blooded killer or was something less sinister at play? This interrupted case study introduces students to hemoglobin binding and carbon monoxide poisoning by working through the details of a fictionalized account of a true-crime story. Topics covered include molecule conformational states, binding affinity, deoxyhemoglobin, oxyhemoglobin, carboxyhemoglobin, and oxygen transport. Students also design an experiment to determine the cause of death of the victim. Prior to beginning the activity students should have some knowledge of the respiratory and circulatory systems and be familiar with oxygen binding curves. Detailed understanding of hemoglobin conformational changes is not necessary since this information is covered in the case. Students will also learn briefly about the electromagnetic spectrum and visible light. Originally developed for a non-majors, pre-nursing anatomy and physiology course, the case is also appropriate for use in any of the following courses: introductory biochemistry, introductory biology, introductory chemistry, nursing, exercise physiology, or possibly even introductory physics.


  • Describe the function of hemoglobin in the body and be able to sketch the molecule.
  • Describe cooperative binding, specifically how the tensed and relaxed states of hemoglobin relate to oxygen loading and unloading.
  • Compare and contrast the relationship between carbon monoxide or oxygen and hemoglobin, specifically related to binding affinity, molecule state, and light absorption.
  • Explain how carbon monoxide poisoning can lead to hypoxic tissue injuries.
  • Read an oxygen-hemoglobin saturation curve and describe variables that result in right- and left-shifted curves.
  • Design an experiment to support or refute a hypothesis.


hemoglobin; oxygen; carbon monoxide; binding curve; red blood cells; respiration; oxygen transport; hypothesis; scientific method; circulatory system; blood; electromagnetic spectrum;

Topical Areas

Scientific method, Scientific argumentation

Educational Level

Undergraduate lower division, Undergraduate upper division, Clinical education



Type / Methods




Subject Headings

Biochemistry  |   Biology (General)  |   Chemistry (General)  |   Forensic Science  |   Medicine (General)  |   Nursing  |   Physiology  |   Science (General)  |   Sports Science  |   Toxicology  |  

Date Posted


Teaching Notes

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Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Supplemental Materials

The animiations below are helpful for visualizing conformational changes in hemoglobin. (Credit: Janet Iwasa, CC BY-NC-ND 3.0 US,

  T to R transition of hemoglobin
  Conformational changes

Answer Key

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Barry Markillie
Cape Fear Community College
Wilmington, NC

The case study has a mistake. When the water distinguished the flame on the stove, the gas that leaked into the room wasn't CO. Gas stoves are propane or natural gas, neither which will cause the symptoms of toxic carbon monoxide.

Perhaps now that is the case, but from the story we used as inspiration this doesn’t seem to be true. In the 1920s illumination gas was used for stoves and contained CO. See the article by the author of Poisoner’s Handbook:
“During the 1920s, many homes—especially those in tenements and in the poorer neighborhoods—had yet to be wired for electricity. The lights and the stove were fed by illuminating gas, another name for a mixture rich in carbon monoxide, hydrogen, methane, and other gases which, far too often, leaked from poorly joined fittings and cheap fixtures.”