By analyzing urea in 1932, Krebs had already appreciated that the main mechanisms that support life are cycles. The citric acid cycle or Krebs cycle, published by him in 1937, explains life.
Lipids, carbohydrates and amino acids that constitute the food are chemically broken before triggering successively ten catalyzed chemical reactions within the cell, producing the energy that activates the respiration. It is a cycle because the last chemical reaction recreates the molecule that receives the organic substances in the cell. The process is endless as far as the animal injects food.
The Krebs cycle applies to all living beings including bacteria and appeared when the level of oxygen increased on Earth two billion years ago. This is one of the most basic discoveries in the history of biology.
On July 14 in London, Sotheby's sells the Nobel medal of Krebs in its original case along with his Nobel diploma in one lot estimated £ 250K, lot 56.
Hans Adolf Krebs was a Jew. Expelled from Germany by the Nazis in 1933, he was highly welcomed in England and is considered a British scientist, naturalized in 1939. The lot of his Nobel Prize is sold for the benefit of The Sir Hans Krebs Trust, a newly created charity, one of whose goals is to support researchers in biology or medicine prevented by persecution to work in their home country.