Yeast Fermentation in Beverage Production

Steps:

• Identify the biological process: Yeast is a microorganism used in brewing and winemaking to convert sugars from grains or fruits.
• Recall the type of respiration: In low-oxygen environments like fermentation vats, yeast performs anaerobic respiration.
• Understand the products: This process breaks down glucose into ethanol (alcohol) and carbon dioxide.
• Match to question: The primary purpose is ethanol production for alcoholic beverages.

Why B is correct:

• Fermentation is defined as the anaerobic breakdown of sugars by yeast, producing ethanol as the main product (C6H12O6 → 2C2H5OH + 2CO2).

Why the others are wrong:

• A: Yeast uses anaerobic fermentation, not aerobic respiration, which would produce CO2 and water without alcohol.
• C: CO2 release is a byproduct that creates fizz, but not the main role—ethanol is the key product.
• D: Reducing sugar is incidental; the goal is to create alcohol, not just lower sugar content.

Final answer: B