Krebs is best known for his identification of the citric acid cycle, also known as the Krebs cycle, the key sequence of metabolic chemical reactions that produces energy in cells.
Krebs became professor of biochemistry at the University of Sheffield in 1945.
HansAdolfKrebs won the 1953 Nobel Prize for physiology or medicine, which he shared with American biochemist Fritz Albert Lipmann (1899-1986), for his studies of intermediary metabolism, especially his discovery of the metabolic pathway known as the tricarboxylic acid (TCA) cycle, or Krebs cycle, the major source of energy in living organisms.
At the University of Freiburg (1932), Krebs discovered (with the German biochemist Kurt Henseleit) a series of chemical reactions (now known as the urea cycle) by which ammonia is converted to urea in mammalian tissue; the urea, far less toxic than ammonia, is subsequently excreted in the urine of most mammals.
In 1937 Krebs demonstrated the existence of a cycle of chemical reactions that combines the end-product of sugar breakdown, later shown to be an "activated" form of the two-carbon acetic acid, with the four-carbon oxaloacetic acid to form citric acid.
Krebs served on the faculty of the University of Oxford from 1954 to 1967.