Hans Krebs

Biography

Sir Hans Adolf Krebs, born on August 25, 1900, in Hildesheim, Germany, became one of the most important biochemists of the twentieth century. He studied at several top universities in Germany, including the University of Göttingen, the University of Freiburg, the University of Hamburg, Ludwig-Maximilians-Universität München, and Humboldt-Universität zu Berlin. This education gave him a strong background in medicine and natural sciences. Early in his career in Germany, he worked with some of the best researchers of the time and gained a reputation as a careful and creative lab scientist.

Krebs is most famous for discovering two key chemical reaction sequences in the cells of almost all oxygen-breathing organisms. In 1932, he identified the urea cycle, which explains how mammals turn toxic ammonia into water-soluble urea for excretion. More famous is his discovery in 1937 of the citric acid cycle, also known as the Krebs cycle. This cycle shows how cells get most of the chemical energy stored in food, producing far more ATP than simpler methods like glycolysis. This finding changed how we understand cellular respiration and how living things survive at the molecular level. Later, with Hans Kornberg, Krebs discovered the glyoxylate cycle, a variation of the citric acid cycle found in plants, bacteria, protists, and fungi.

In 1933, Krebs had to leave Nazi Germany due to discriminatory laws and moved to England, where he continued his research at the University of Cambridge and later at the University of Sheffield. His work at Sheffield was particularly successful, leading to his recognition by the Nobel Committee. In 1953, Krebs won the Nobel Prize in Physiology or Medicine, sharing it with Fritz Albert Lipmann, for his discovery of the citric acid cycle. That year, he also received the Albert Lasker Award for Basic Medical Research, a major American medical honor.

In 1954, Krebs became the Whitley Professor of Biochemistry at the University of Oxford, a role he held until 1967. While at Oxford, he continued his research and guided new biochemists. His work earned him several honors, such as the Royal Medal in 1954, an honorary doctorate from the University of Paris in 1956, an honorary doctorate from the Hebrew University of Jerusalem in 1960, the Copley Medal in 1961, and the Croonian Medal and Lecture in 1963. In 1966, Hildesheim, his birthplace, made him an honorary citizen, and the University of Bordeaux awarded him an honorary doctorate. He received the Otto Warburg Medal in 1969.

Krebs died on November 22, 1981, in Oxford, the city he had lived in during his later years. His death marked the end of a career that changed the biological sciences and his work still supports research in metabolism, medicine, and cell biology.