Question

Which of the following products are obtained by anaerobic respiration from yeast?

• A. Carbon dioxide
• B. Beer and wine
• C. Alcohol
• D. All of these

Answer 1

The correct option is D

All of these

The correct option is D.

Explanation of the correct answer:

1. Yeast is a facultative anaerobe.
2. Anaerobic respiration is respiration in the absence of oxygen, using electron acceptors.
3. The end product of anaerobic respiration is alcohol.
4. Yeast is used in the production of alcohol, beer, and wine and also to raise dough in the bread-making industries.
5. The chemical equation is: C₆H₁₂O₆ ⇢ 2C₂H₅OH + 2CO₂ + 2ATP (Glucose → ethanol + carbon dioxide + energy).
6. Thus, all of these options are correct.

Explanation of the incorrect options:

Option A:

Fermentation of yeast in anaerobic conditions leads to the production of carbon dioxide and ethanol.

Option B:

In the absence of oxygen, yeast converts sugars into alcohol and carbon dioxide which is used to make wine and beer.

Option C:

Incomplete oxidation of glucose makes pyruvic acid, which then gets converted into alcohol and carbon dioxide.

Final answer: Beer, wine, alcohol, and carbon dioxide are products obtained by anaerobic respiration from yeast.