Peter Dennis Mitchell was born on September 29, 1920, in Mitcham, UK. He studied natural sciences with a focus on biochemistry at the University of Cambridge, UK. He received his Ph.D. there in 1951 for work on penicillin [1].

In 1955, Mitchell set up a biochemical research unit at the University of Edinburgh, UK, where he was appointed a Senior Lecturer in 1961 and Reader in 1962. Together with his former research colleague Jennifer Moyle, he then remodeled Glynn House, a mansion near Bodmin, UK, and converted it into a research institute. In 1964, the team founded Glynn Research Ltd., a charitable company aiming to promote fundamental biological research at Glynn House. Mitchell served as Research Director there from 1964 to 1986.

Mitchell is well-known for his research on the biosynthesis of adenosine triphosphate (ATP, pictured). ATP provides the energy for many processes in living organisms. This was known at the time, but the biochemical mechanism by which cells oxidize nutrients and produce ATP in mitochondria was not understood. Mitchell proposed the so-called chemiosmotic theory of ATP synthesis in 1961 [2]. The theory states that most ATP in respiring cells is synthesized using the movement of protons along an electrochemical gradient (i.e., chemiosmosis) across the inner membranes of mitochondria as a driving force. The process, known as oxidative phosphorylation, couples the oxidation of energy-rich molecules such as glucose with the synthesis of ATP from adenosine diphosphate (ADP). Energy is released via redox reactions catalyzed by enzymes and used to create a proton gradient. When protons flow back across the membrane, the previously stored energy can be used by ATP synthase, an enzyme that converts ADP to ATP in a phosphorylation reaction.

For this discovery, Mitchell was awarded the 1978 Nobel Prize in Chemistry “for his contribution to the understanding of biological energy transfer through the formulation of the chemiosmotic theory.” Among many other honors, he received the Sir Hans Krebs Medal in 1978, the Copley Medal from the Royal Society, UK, in 1981, and several honorary doctorates. He was elected a Fellow of the Royal Society and a Member of the American Academy of Arts and Sciences and of the U.S. National Academy of Sciences. Peter D. Mitchell died on April 10, 1992.

Peter D. Mitchell is the answer to Guess the Chemist (105).

 

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References

• [1] The rates of synthesis and proportions by weight of the nucleic acid components of a Micrococcus during growth in normal and in penicillin containing media with reference to the bactericidal action of penicillin,
  P. D. Mitchell,
  Thesis, University of Cambridge, 1951.
• [2] Coupling of Phosphorylation to Electron and Hydrogen Transfer by a Chemi-Osmotic type of Mechanism,
  P. D. Mitchell,
  Nature 1961, 191, 144–148.
  https://doi.org/10.1038/191144a0

Sources

• Obituary: Peter Dennis Mitchell, 29 September 1920 – 10 April 1992,
  E. C. Slater,
  Biogr. Mem. Fellows Royal Soc. 1994, 40, 281–305.
  https://doi.org/10.1098/rsbm.1994.0040

Selected Publications

• Chemiosmotic Coupling in Oxidative and Photosynthetic Phoyphorylation,
  P. D. Mitchell,
  Biol. Rev. 1966, 41, 445–501.
  https://doi.org/10.1111/j.1469-185X.1966.tb01501.x
• Respiration-driven proton translocation in rat liver mitochondria,
  P. D. Mitchell, J. Moyle,
  Biochem. J. 1967, 105, 1147–1162.
  https://doi.org/10.1042/bj1051147
• The protonmotive Q cycle: A general formulation,
  P. D. Mitchell,
  FEBS Lett. 1975, 59, 137–139.
  https://doi.org/10.1016/0014-5793(75)80359-0
• Possible molecular mechanisms of the protonmotive function of cytochrome systems,
  P. D. Mitchell,
  J. Theor. Biol. 1976, 62, 327–367.
  https://doi.org/10.1016/0022-5193(76)90124-7
• Oxidative Phosphorylation and Photophosphorylation,
  P. D. Boyer, B. Chance, L. Ernster, P. D. Mitchell, E. Racker, E. C. Slater,
  Ann. Rev. Biochem. 1977, 46, 955–966.
  https://doi.org/10.1146/annurev.bi.46.070177.004515
• Keilin’s respiratory chain concept and its chemiosmotic consequences,
  P. D. Mitchell,
  Science 1979, 206, 1148–1159.
  https://doi.org/10.1126/science.388618

 

Update (May 19, 2023)
The article originally had a typographical error in the town name of Bodmin; this has been corrected.