Fermentation questions.

Question

Fermentation questions.

Fermentation

1. Which gas is produced during the process of fermentation and is measured in fermentation tubes?
2. What was the negative control in this experiment? 
3. When yeast is exposed to sugar and begin to ferment, which sugar would lead to great fermentation, glucose or starch? Why?
4. If yeast cells are not able to utilize a carbohydrate for energy, what does that suggest to you about the enzymes found in the yeast cells?

Answer 1

1. CO2 (carbon dioxide) is produced in fermentation via process called decarboxylation
2. A negative control would be pure water as no significant amount CO2 is expected to be dissolved in it.
3. Glucose would yield to greater rate of fermentation because the yeast has to first break starch into glucose monomers, which takes time and additional energy to do. Only glucose can be fermented right away whereas starch, that is a chain of glucose connected via beta glycosidic linkages, cannot be fermented directly.
4. It would suggest that they lack enzymes that can perform beta oxidation - an essential biochemical step in breaking down carbohydrate chains, such as fats, into Acetyl-CoA molecules.