Question

What amount of energy is released from glucose during lactic acid fermentation?

• A. Approximately 15%
• B. More than 18%
• C. About 10%
• D. Less than 7%

Answer 1

The Correct Option is D

Fermentation only releases less than seven percent of the energy found in glucose, and not all of it is stored as ATP.

So, the correct option is (D): Less than 7%

Answer 2

Explanation: Lactic acid Fermentation releases less than 7% of the energy found in glucose, and not all of it is stored as ATP.

• The process of producing ATP in the absence of oxygen, through glycolysis alone is called fermentation.
• Glycolysis breaks glucose molecules into 2 molecules of pyruvate resulting in 2 ATP and 2 NADH molecules.
• Lactic acid fermentation is carried out by Lactobacillus.
• This type of fermentation involves anaerobic respiration.

In Lactic acid fermentation, 3-carbon pyruvate is converted into 3-carbon lactic acid (C3H6O3) and produces NAD+, allowing glycolysis to continue to make ATP in low-oxygen conditions. As there is a limited supply of NAD+ available in a given cell, the electron acceptor is regenerated to allow ATP production to continue. To do this, NADH regenerates NAD+ by donating its excess electrons to the pyruvate molecules. Pyruvate is reduced to produce lactic acid. Pyruvate is converted to lactic acid through lactic acid fermentation, which also produces NAD+ from NADH.

So, the correct option is (D): Less than 7%