Question

Fermentation is a type of anaerobic respiration that occurs in yeast and bacteria. What is the function of fermentation?
I. Regenerate $NA{D}^{+}$ from NADH
II. Produce oxygen as a waste product
Ill. Produce ATP

• A. I only
• B. II only
• C. III only
• D. I and II only
• E. I and III only

Answer 1

Answer: (A)

I only

Fermentation is a type of cellular respiration found in some microorganisms which do not require oxygen i.e. it is anaerobic respiration and results in the formation of ethanol from glucose and release of some amount of energy.

In yeast and bacteria, enzyme is released by the cells in the surrounding medium and the breakdown of substrate takes place outside the cell. The substrate is pyruvate which is formed by glycolysis. The end product is ethyl alcohol, CO₂ and energy. Also, NADH₂ is converted into NAD⁺.

Hence, NAD⁺ is regenerated from NADH.

So, the correct answer is 'I only'.