Question

Who coined the term zymase for enzymes in yeast?
a. Buchner
b. Kuhne
c. Pasteur
d. Sumner

Answer 1

Hint: The cell-free extract for enzymes was produced by joining dry yeast cells, quartz and kieselguhr, and after pulverizing the yeast cells with the help of a mortar and pestle. After the completion of this step, the moist mixture would be put through a press and when this ensuing "press juice" had glucose, fructose, or maltose added, carbon dioxide was seen to develop, sometimes for days.

Complete answer:
> Kuhne was a German physiologist born in Hamburg, best recognized today for proposing the word enzyme.

> Pasteur was a French chemist well-known for his discoveries of the values of microbial fermentation, vaccination, and pasteurization.

> Sumner was an American chemist who exposed that enzymes can be crystallized, for which he got the Nobel Prize in Chemistry in 1946.

> Eduard Buchner proposed the term zymase for the composite of biocatalysts extracted from yeast and involved in alcoholic fermentation. In 1903, Buchner extracted the first enzyme. He is praised for the real discovery of enzymes and was awarded a Nobel prize for this work. In 1897, he first isolated zymase from cells of yeast. He also gives one hypothesis that proteins are secreted by yeast cells.

Hence, the correct answer is option (A).

Note: Buchner hypothesized that yeast cells exude proteins into their environment for ferment sugars. It was later shown that fermentation arises in the yeast cells. Thus, the formation of biocatalyst from the yeast is discovered by Bucher. This dealt yet one more blow to vitalism by revealing that the presence of living yeast cells was not required for fermentation.