EuroMUG'99 -- 28-29 October 1999 -- Cambridge, UK
Jeremy Yang

Biogenesis studies, Harold Morowitz

The Origin of Intermediary Metabolism, Morowitz, et al.



The core of intermediary metabolism in autotrophs is the citric acid cycle. In a specific group of chemoautotrophs the reductive citric acid cycle is an engine of synthesis, taking in CO2 and synthesizing the molecules of the cycle. We have examined the chemistry of a model system of C, H, and O that starts with carbon dioxide and reductants and uses redox couples as the energy source. To inquire into the reaction networks that might emerge, we start with the largest available database of organic molecules, Beilstein on-line, and prune by a set of physical and chemical constraints applicable to the model system. From the 3.5 million entries in Beilstein we emerge with 146 molecules that contain all 11 members of the reductive citric acid cycle. A small number of selection rules generates a very constrained subset, suggesting that this is the type of reaction model that will prove useful in the study of biogenesis. The model indicates that the metabolism shown in the universal chart of pathways is central to the origin of life, emerges from organic chemistry, and may be unique.

Selected references:

  1. Energy Flow in Biology. Academic Press, 1968, Morowitz, Harold J.
  2. Mayonnaise and The Origin of Life, Thoughts of Minds and Molecules. Charles Scribner's Sons, 1985, Morowitz, Harold J.
  3. The Thermodynamics of Pizza. Rutgers University Press, 1991, Morowitz, Harold J.
  4. Beginnings of Cellular Life, Metabolism Recapitulates Biogenesis. Yale University Press, 1992, Morowitz, Harold J.
  5. Morowitz, Harold J., Eta Peterson, and Sherwood Chang. Origin of Life and Evolution of the Biosphere 25, p.395-399 (1995) The Synthesis of Glutanic acid in the absence of Enzymes: Implications for Biogenesis.

EuroMUG'99 -- 28-29 October 1999 -- Cambridge, UK

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