Question

The function of zymase is to:
(A) change starch into sugar
(B) ferment glucose to alcohol and carbon dioxide
(C) change malt sugar into glucose
(D) change starch into malt sugar and dextrin

Answer 1

Hint When starch is broken down into simple sugars, other enzymes in yeast act upon the simple sugars to produce alcohol and carbon dioxide. In the process of bread making, this step is called fermentation.

Complete answer:
An enzyme is a substance which acts as a catalyst in living organisms, it regulates the rate at which chemical reactions proceed without itself being altered. The biological processes that occur within all living organisms are mostly chemical reactions, and most of them are regulated by enzymes.
Fermentation is a process that makes chemical changes in the organic substrates through the action of enzymes. In biochemistry, it is defined as the extraction of energy from carbohydrates in the absence of oxygen.
Zymase is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide. The chemical reaction for this process:
${{C}_{6}}{{H}_{12}}{{O}_{6}}(aq)\xrightarrow{zymase}2{{C}_{2}}{{H}_{5}}OH(aq)\,+\,C{{O}_{2}}(g)$
Here fermentation of glucose is taking place which is also called sugar. Carbon Dioxide gas will be released during the fermentation process.

So, the correct option will be (b).

Note: Sucrose (sugar) can't be fermented directly by the enzyme zymase. One of yeast's other enzymes, like invertase, must first digest sucrose into glucose and fructose. Then the enzyme zymase ferments these sugars.