Emil Fischer

Emil Fischer was born on 9 October 1852 in Euskirchen, Prussia, and died on 15 July 1919 in Berlin. He earned a PhD at the University of Strasbourg in 1874 under Adolf von Baeyer, then held professorships at Munich, Erlangen and Wurzburg before moving to Berlin in 1892. He devised the Fischer projection, a standard way of drawing three-dimensional sugar and amino acid structures as flat diagrams, and used it through the 1880s and 1890s to work out the structures and stereochemistry of glucose and the other simple sugars, extending the molecular stereochemistry Louis Pasteur had opened in 1848 into a systematic account of an entire class of biological molecules. In 1894, testing how different yeast and plant enzymes acted on closely related sugar stereoisomers, he found that each enzyme acted on only one of a near-identical pair and never the other, and proposed that an enzyme and its substrate must fit each other with precise geometric complementarity, like a lock and its key, in order to react; the phrase and the model became the standard explanation of enzyme specificity for roughly the next sixty years. He also synthesized purines, including caffeine and uric acid, and was awarded the 1902 Nobel Prize in Chemistry for his work on sugar and purine synthesis. Two of his three sons died during the First World War, one killed in action and one by suicide after compulsory military call-up; diagnosed with intestinal cancer as the war ended, Fischer died by his own hand in Berlin in July 1919.