Question

Question: Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

1. the citric acid cycles
2. the electron transport chain
3. glycolysis
4. reduction of pyruvate to lactate

Short answer

1. The statement "the citric acid cycle" is false.
2. The statement "the electron transport chain" is false
3. The word "glycolysis" is true.
4. The statement "reduction of pyruvate to lactate." is false.

Step-by-step solution

Metabolic pathways

Metabolic pathways are the chemical reaction that takes place within the human body for survival and reproduction.

Prokaryotic organism undergoes an easier metabolic process compared to eukaryotic organism. Eukaryotic organisms have a complex body organization.

Explanation of option '(A)'

The citric acid cycle does not involve the glucose molecule. Instead, the major metabolite of this process is the acetyl CoA. In the process, carbon dioxide is released as a product.

Thus, the citric acid cycle is not the common metabolic pathway for cellular respiration and the fermentation of glucose.

Therefore, the given statement is false

Explanation of option '(B)'

The electron transport chain is the mechanism by which the electrons are shifted to oxygen. It is a series of reaction that releases energy. The primary work of the electron transport chain is involved in making ATP.

Thus, the electron transport chain is not the common metabolic pathway of cellular respiration and fermentation.

Therefore, the given statement is false.

Explanation of option '(C)'

Pyruvate is the end product that is formed from glycolysis. The body utilizes this pyruvate molecule in ways such as cellular respiration and fermentation.

The cellular respiration takes place in oxygen, followed by a series of reactions after glycolysis, such as the Krebs cycle and electron transport chain. Fermentation is the process by which the pyruvate is converted into ethanol or lactate.

Thus, glycolysis is the common metabolic pathway for cellular respiration and fermentation.

Therefore, the given statement is true.

Explanation of option '(D)'

The conversion of pyruvate to lactate happens in the absence of oxygen. This process is the mechanism of fermentation.

Thus, converting pyruvate to lactate is not the only fate of glucose that undergoes the glycolysis mechanism.

Therefore, the given statement is false.