You have decided to try to make your own wine by adding yeast to a sweet grape juice.After allowing plenty of time for the yeast to grow,you find that although the sugar levels in the juice are decreased,there is no alcohol in the mixture.What could have been the reason fermentation did not occur?
A) More sugar needs to be added, yeast need a lot of energy before they produce alcohol.
B) Less sugar is needed in the juice, high sugar concentration causes cellular respiration to occur instead of fermentation.
C) Yeast can not ferment grapes, only bacteria can.
D) The mixture needs less oxygen, yeast only produce alcohol in the absence of oxygen.
E) The mixture needs more carbon dioxide.

Question

Quizplus · Accepted Answer

Yeast perform fermentation to produce alcohol in anaerobic conditions (absence of oxygen). If there is too much oxygen, yeast will undergo aerobic respiration instead, which does not produce alcohol.

You Have Decided to Try to Make Your Own Wine