Question

When yeast ferments glucose, the products obtained are

• A. ethanol and CO₂
• B. methanol and CO₂,
• C. ethanol and water
• D. water and CO₂

Answer 1

Answer: (A)

When oxygen is not available (anaerobic condition) yeast and some other microbes convert pyruvic acid into ethyl alcohol. It is a two step process. In the first step pyruvic acid is decarboxylated to yield acetaldehyde and CO₂.Pyruvic acid is a 3-C compound and acts as electron donor while acetaldehyde is the electron acceptor.