Background

In a series of rather simple experiments, Stokes (1) showed he could mimic the reversible red-to-purple color changes of blood in our bodies by the alternate use of inorganic reducing agents and oxygen. Clearly the basic chemical concept of reversible oxidation/reduction provided an easily understood model for interpreting the complex processes going on in the body. While Stokes' model had considerable merit, it does not correspond to the modern view nor was it totally consistent with all of his observations. For example, he noted the anomalous behavior of carbonic acid which, though not a reducing agent, caused blood solutions to change from red to purple. Forty years later, Bohr et al. (2) showed that the anomalous effects of CO₂ (= carbonic acid when dissolved in water) on oxygen binding to hemoglobin were specific and physiologically important. Douglas et al. (3) confirmed and extended these observations. By then, nearly half a century after Stokes' wrote his article and after J. J. Thomson discovered the electron (1897), confusion persisted over the difference between oxidation and oxygenation.

The article by Conant that follows does not cite Stokes' article. However, Stokes' title, "On the Reduction and Oxidation of the Colouring Matter of the Blood," would have been an appropriate title for Conant's article. In this article, Conant cleanly distinguished oxidation/reduction from oxygenation/ deoxygenation of hemoglobin in a single experiment. Here and in a following paper (4), he provides strong chemical evidence for the chemical relationship between methemoglobin and other forms of hemoglobin.

James Bryant Conant (1893 - 1978)

Who would have thought that ten years after writing an article on the electrochemistry of hemoglobin, the author would begin a 20 year tenure as the president of Harvard? Who would have thought that this organic chemist (5) would be directly involved in the Manhattan Project and the decision to drop the atomic bomb on Hiroshima (6)? Who would have thought that this distinguished college administrator and government advisor would become ambassador to Germany (7) or become a leading authority on high school education in the United States who wrote several influential books on the subject (8-11)? And who would have thought that this same person, James Bryant Conant, would have provided a model for teaching science from the perspective of historical case studies (12,13), a theme that strongly influences CHEM-342, the course you are taking?

James Bryant Conant was a distinguished chemist, educational scholar, college administrator, government advisor, statesman, and author. Despite his high public profile, his private life was private. For example, in the first draft of his autobiography (14), he did not mention his wife (15) who was the daughter of his Ph.D. thesis advisor, 1914 Chemistry Nobel Laureate Theodore William Richards. Although many of the authors of the articles you will read on hemoglobin became well known, perhaps with the exception of Linus Pauling, none was as prominent as James Bryant Conant.

* Indicates articles that are in the course reader.

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Last updated: 6 March 2008 by Hal White
Copyright 1999, 2005, Department of Chemistry and Biochemistry, University of Delaware