Question

During fermentation alcohol is formed from

• A. Sugar
• B. Protein
• C. Carbon dioxide and water
• D. None of the above

Answer 1

Answer: (A)

Sugar

Fermentation is an energy releasing process in which substrate like sugar is oxidized into alcohol. It is an anaerobic process. It occurs in yeasts, some bacteria and muscle cells. Under anaerobic conditions, pyruvic acid is either converted ethanol in alcohol fermentation. During alcohol fermentation, pyruvic acid is first converted to acetaldehyde in presence of enzyme pyruvate decarboxylase. The acetaldehyde is then converted into ethyl alcohol by enzyme alcohol dehydrogenase.

Thus, the correct answer is option A.