Zymase is an enzyme complex that catalyzes glycolysis, the fermentation of sugar into ethanol and carbon dioxide. As the conversion takes place, the reaction will gradually slow down. They occur naturally in yeasts. See alcohol dehydrogenase. Zymase was first isolated from the yeast cell in 1897 by a German chemist named Eduard Buchner who fermented sugar in the laboratory. British chemist Sir Arthur Harden divided zymase into two varieties (dialyzable and nondialyzable) in 1905. Zymase is also… (More on Zymase)