Born: 12 October 1865, Manchester, United Kingdom
Died: 17 June 1940, Bourne, United Kingdom
Affiliation at the time of the award: London University, London, United Kingdom
Prize motivation: "for their investigations on the fermentation of sugar and fermentative enzymes."
Prize share: 1/2
The fermentation of sugar into alcohol is the basis for bread as well as beer and wine. After Eduard Buchner discovered that fermentation is driven by chemical substances, enzymes formed by yeast fungi, details involved in the process still needed to be clarified. At first it was believed that fermentation was caused by a uniform enzyme, but when Arthur Harden filtered yeast extract through a very fine filter, he found two different substances, both of which were essential to the fermentation process: the real enzyme and a coenzyme. He showed that phosphoric acid also plays an important role in the process.