Humber Admissions Practice Test

What is an intermediate product of glycolysis?

1. ATP

2. Carbon dioxide

3. Pyruvic acid

4. Acetyl-CoA

The correct answer is: Pyruvic acid

Glycolysis is a metabolic pathway that converts glucose into pyruvate, producing energy in the form of ATP and NADH in the process. Pyruvic acid, also known as pyruvate, is the end product of glycolysis and serves as an important intermediate in several metabolic processes. In the context of glycolysis, pyruvate represents a crucial junction point. After glycolysis, pyruvate can be further oxidized in the presence of oxygen during aerobic respiration to produce Acetyl-CoA, which enters the Krebs cycle. Alternatively, in anaerobic conditions, pyruvate can be converted into lactic acid (in animals) or ethanol and carbon dioxide (in yeast and some bacteria). While ATP is produced during glycolysis, it is not considered an intermediate product; instead, it is a direct product and energy currency of the cell. Carbon dioxide is a byproduct that can be produced in other stages of cellular respiration but is not directly generated during glycolysis itself. Acetyl-CoA is formed from pyruvate in subsequent metabolic pathways rather than being a product of glycolysis. Therefore, identifying pyruvic acid as the intermediate product of glycolysis is accurate because it captures the role of pyruvate in connecting