<P> Buchner hypothesized that yeast cells secrete proteins into their environment in order to ferment sugars . It was later shown that fermentation occurs inside the yeast cells . </P> <P> British chemist Sir Arthur Harden divided zymase into two varieties (dialyzable and nondialyzable) in 1905 . </P> <P> Some science historians suggest that Eduard Buchner, in his 1897 work, merely repeated experiments already made by Antoine Béchamp in 1857 . This is not the case: what Buchner obtained with yeast zymase, and without yeast cells, was alcoholic fermentation, while Béchamp had explicitly stated that, in absence of yeast cells, and by use of what he, also, called "zymase", he obtained only sugar inversion and no alcoholic fermentation . According to K.L. Manchester, what Béchamp called "zymase" was invertase . </P>

Who coined the term zymase for enzymes in yeast