Hans Krebs

Origins and early life

Hans Adolf Krebs was born in Hildesheim, Germany, on 25 August 1900, the middle of three children of Georg Krebs, an ear, nose and throat surgeon, and Alma Davidson; he was of Jewish ancestry.

Work and career

He was conscripted near the end of the First World War, six months short of finishing school, and returned to take up medicine. He was working in Germany when the Nazis came to power and dismissed Jewish scientists from their posts; he left for England in 1933 and made the rest of his life there. In 1937, at Sheffield, he described the sequence of reactions that carries the name he is known by: the citric acid cycle, or Krebs cycle, the ring of chemical steps by which cells burn food with oxygen to release the energy that everything alive runs on.

He had already worked out the urea cycle, by which the body disposes of nitrogen. He shared the Nobel Prize in Physiology or Medicine in 1953 and was knighted. He called his nineteen years in Sheffield happy ones; his son John became an eminent ornithologist and a member of the House of Lords. He died in Oxford on 22 November 1981.