Which of the following is produced during glycolysis?

During glycolysis, glucose, a six-carbon sugar, undergoes a series of enzymatic reactions that ultimately break it down into two three-carbon molecules of pyruvate. This process occurs in the cytoplasm of the cell and is the first step in cellular respiration.

In addition to pyruvate, glycolysis generates NADH, which is produced when NAD+ is reduced by accepting electrons. The production of both pyruvate and NADH is significant because pyruvate can be further processed in aerobic conditions to enter the Krebs cycle, and NADH serves as an important electron carrier for the electron transport chain, facilitating ATP production.

The other options relate to metabolic processes outside of glycolysis. For instance, carbon dioxide is produced during the later stages of cellular respiration, specifically during the Krebs cycle, while acetyl-CoA is generated from pyruvate before it enters the Krebs cycle. FADH2 is also produced in the Krebs cycle, not glycolysis. Thus, NADH and pyruvate are the key products formed during glycolysis, confirming the correctness of the answer.