Sir Hans Adolf Krebs was born at Hildescheim, Germany, on Aug. 25, 1900. He was the son of George Krebs, M.D., an E.N.T. Surgeon. Krebs got his early education at Hildescheim and then between 1918 and 1923 studied Medicine at the University of Gottingen, Freiburg and Berlin. He obtained M.D. degree in 1925 from University of Hamburg. For the next five years until 1930, he was associated with Professor Otto Warburg doing research in biochemistry at the Kaiser Wilhelm Institute for Biology at Berlin-Dahlem.
In 1930, he took up a chemical appointment in biochemistry in Freiburg. When Nazis came to power, the National Socialist Government terminated his appointment in June 1933, and he went at the invitation of Sir Fredrick Gowland Hopkins to the school of Biochemistry, Cambridge, where he was able to continue his research work with the continued support of Rockefeller Foundation.
Two years later, in 1935, he was appointed Lecturer in Pharmacology at the University of Sheffield, and in 1938 Lecture-in-Charge of Department of Biochemistry then newly founded there.
In 1945, Krebs’ appointment was raised to that of Professor and of Director of a Medical Research Council’s Research Unit established in his Department In 1954, Professor Krebs occupied Whitley Chair of Biochemistry in the University of Oxford and the Medical Research Council’s Unit for Research in Cell Metabolism was transferred to Oxford. Krebs retained this appointment till his retirement in 1967. Thereafter, he continued his research work in the Nuffield Department of Clinical Medicine in Oxford and he was appointed Visiting Professor of Biochemistry at the Royal Free Hospital, London.
Krebs’ researches have mainly been concerned with various aspects of intermediary metabolism. Among the subjects he had studied are the synthesis of urea in the mammalian liver (‘Urea Cycle’), the synthesis of uric acid and purine bases in birds, the intermediary stages of the oxidation of food-stuffs, the mechanism of the active transport of electrolytes and the relations between cell respiration and the generation of adenosine triphosphates.
In 1937, Krebs was able to demonstrate the existence of a cycle of chemical reactions (now known as citric acid cycle) that combines the end-product of sugar breakdown (later shown to be active 2-C unit, acetyl-CoA) with the 4-C oxaloacetate to form citric acid. This cycle regenerates oxaloacetate through a series of intermediate compounds liberating CO, and electrons. The latter are immediately utilized to form high energy phosphate bonds in the form of adenosine triphosphates.
In recognition for his discovery of citric acid cycle, Krebs was awarded Nobel Prize of 1953 in Physiology or Medicine which he jointly shared with Fritz Albert Lipmann (for his discovery of coenzyme A and its importance for intermediary metabolism).
In his presentation speech of the 1953 Nobel Prize Award Ceremony in Physiology or Medicine, Professor E. Hammarsten, member of the Staff of Professors of the Royal Caroline Institute remarked … “Doctor Krebs, the Staff of Karolinska Instituted is pleased to reward your achievement when with intuitive perception you were able to see in the chaotic and fragmentary mass of known enzymatic processes the way, the primary pathway, of combustion, and with consummate skill to prove the reality of your vision. This prize is in corroboration of the general agreement that you have laid a foundation, which will last for all time and that we have already witnessed the great development of constructive work founded in your pioneer achievement.”
Krebs was elected Fellow of the Royal Society of London in 1947. In 1954, the Royal Medal of the Royal Society, and in 1958 the Gold Medal of the Netherlands Society for Physics, Medical Science and Surgery were conferred on him. He was knighted in 1958.
Professor Krebs was also conferred with honorary degrees by several Universities such as Chicago, Freiburg, Paris, Glasgow, London, Sheffield, Leicester, Berlin and Jerusalem.
Hans Krebs married Margaret Cicely Fieldhouse, of Wickersley, Yorkshire in 1938. They were blessed with two sons, Paul and John and one daughter, Helen.
Sir Hans Adolf Krebs died on November 22, 1981 in London.