Hugo Theorell


Axel Hugo Theodor Theorell

Photo from the Nobel Foundation archive.

Axel Hugo Theodor Theorell
The Nobel Prize in Physiology or Medicine 1955

Born: 6 July 1903, Linköping, Sweden

Died: 15 August 1982, Stockholm, Sweden

Affiliation at the time of the award: Karolinska Institutet, Nobel Medical Institute, Stockholm, Sweden

Prize motivation: “for his discoveries concerning the nature and mode of action of oxidation enzymes”

Prize share: 1/1


Hugo Theorell was born in Linköping, Sweden. His father worked as a regimental medical officer. Theorell studied medicine at Karolinska Institutet, Stockholm, receiving his degree in 1930. After receiving a Rockefeller Fellowship, he worked with Otto Warburg in Berlin-Dahlem from 1933 to 1935, where he conducted some of his most important work. He became a professor at Sweden's Uppsala University in 1937 and then at Karolinska Institutet in 1959. Theorell was married to concert pianist Margit Alenius and had three sons.


Catalysts are substances that speed up chemical reactions without influencing the end products. Enzymes are catalysts active in biological processes. Hugo Theorell and colleagues investigated how enzymes that promote oxidation reactions are constructed and function. A breakthrough came in 1935 when he demonstrated how a yellow-colored enzyme in yeast had two parts, both of which were crucial to its function. He also explained how iron atoms in many enzymes have an important function in transporting electrons.

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MLA style: Hugo Theorell – Facts. Nobel Prize Outreach AB 2023. Sat. 23 Sep 2023. <>

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