The "Currency of the Cell": Energy Cycles and the Remaking of Metabolism, 1900–1970

Abstract

This dissertation asks how physiologists and biochemists turned metabolism into a problem of molecular energy transformations over the course of the twentieth century. It examines the work of a transatlantic set of researchers who sought to comprehend how animal cells garner energy from ingested nutrient sources to power vital molecular activities. The analysis focuses especially on how these investigators mobilized metaphors to gain insight into the developing field of energy metabolism (later “bioenergetics”). Each chapter tracks the emergence and rise of a specific metaphor in biological energy studies and assesses its practical research implications. The Introduction brings into view the metaphor of the metabolic “cycle,” arguing that such representations persisted across the century. Chapter 1 explores the ways in which muscle researchers like Otto Meyerhof and A.V. Hill constructed the “muscle machine” as their target in investigations of muscle contraction energetics. Chapter 2 scrutinizes the gendered dynamics of the marital scientific research collaboration between Gerty and Carl Cori, through which they came to conceptualize animal sugar metabolism as a “balance sheet.” Chapter 3 looks critically at the advent of the metabolic “pathway” in the work of the Coris, Meyerhof, Hans A. Krebs, and others, arguing that “pathway” construction efforts became emblematic of an energetic approach to “intermediary metabolism.” Chapter 4 investigates the circumstances behind the articulation of the notion of the “energy-rich” phosphate “bond,” described by Fritz A. Lipmann and Herman M. Kalckar in two review articles published independently in 1941. Chapter 5 offers an account of how the organelles named mitochondria acquired their cellular “power plants” reputation through an examination of the investigative programs of David E. Green and Albert L. Lehninger, both of whom bridged structural and functional concerns in their considerations of oxidative phosphorylation. Finally, the Conclusion documents how biochemists came to envision adenosine triphosphate (ATP), a molecule containing two “energy-rich” phosphate bonds, as the cell’s “universal energy currency.” Ultimately, the dissertation argues that by the late twentieth century, biological energy researchers had thoroughly transformed metabolism into a kind of cyclical energetic “economy,” in which biochemical reactions requiring energy were “paid for” by those that released energy.