There is no production of carbon dioxide in glycolysis. Which of the following is the best explanation for this fact?

• A. There are no oxidation or reduction reactions in glycolysis to produce CO₂.
• B. There is very little ATP produced in glycolysis.
• C. The initial steps of glycolysis require an input of energy in the form of ATP (two per glucose).
• D. Glucose contains more carbons than the number of carbons found in the pyruvate products that are produced by glycolysis.
• E. The products of glycolysis contain the same total number of carbon atoms as in the starting material.

Answer: (E)

Verified step by step guidance

1. Begin by understanding the process of glycolysis: it is the metabolic pathway that converts glucose into pyruvate, releasing energy in the form of ATP and NADH.
2. Recognize that glycolysis involves the breakdown of one glucose molecule, which contains 6 carbon atoms, into two molecules of pyruvate, each containing 3 carbon atoms. This means the total number of carbon atoms remains the same throughout the process.
3. Consider the role of oxidation and reduction reactions: glycolysis does involve these types of reactions, but they do not result in the release of carbon dioxide. Instead, NAD+ is reduced to NADH during glycolysis.
4. Understand that carbon dioxide is typically released during the decarboxylation reactions in cellular respiration, such as in the citric acid cycle, not during glycolysis.
5. Conclude that the best explanation for the lack of carbon dioxide production in glycolysis is that the products of glycolysis (pyruvate) contain the same total number of carbon atoms as the starting material (glucose), thus no carbon atoms are lost as CO2.