1861-1947

English biochemist who shared the 1929 Nobel Prize for physiology or medicine with Christiaan Eijkman for discovering the "accessory factors" that are needed for growth and health. These essential dietary factors are now known as vitamins. Hopkins proved that, contrary to prevailing opinion, animals could not live on a diet that only contained pure protein, carbohydrates, and fats, even if mineral salts were added. Hopkins also isolated the essential amino acid known as tryptophan and the tripeptide called glutathione.