Embden, Gustav Georg (1874–1933), German physiological chemist. In 1904 Embden became director of the chemistry laboratory of the medical clinic at the Frankfurt-Sachsenhausen municipal hospital. Eventually the clinic became an institute of the University of Frankfurt am Main. His pioneering studies in the field of physiological chemistry included research on the intermediate metabolic processes in liver tissue. He established the importance of the role of the liver in metabolism. Between 1932 and 1933 he and his assistants succeeded in tracing all of the stages of the breakdown of glycogen in the muscle to lactic acid. He is also credited with isolating several intermediate metabolic products from muscle tissue.
Meyerhof, Otto (1884–1951), German biochemist. Meyerhof held posts in physiology and physical chemistry at Kiel and other German universities. From 1929 to 1938 he headed the department of physiology at the Kaiser Wilhelm Institute for Medical Research in Heidelberg. In 1919 he demonstrated that during muscle contraction in the absence of oxygen, glycogen is converted to lactic acid. In the presence of oxygen, about one-fifth of the lactic acid is oxidized to carbon dioxide and water. The energy produced by this oxidation is then used to regenerate glycogen from the remaining lactic acid. In 1925 Meyerhof successfully extracted from muscle the group of enzymes responsible for the conversion of glycogen to lactic acid. In 1922 he and Archibald Hill shared the Nobel Prize for Physiology or Medicine for their researches into the chemistry of metabolism in muscle.