What is the role of coenzyme A in cellular respiration?

Coenzyme A plays a crucial role in cellular respiration by facilitating the formation of acetyl-CoA. Acetyl-CoA is a key intermediate in the metabolic pathway that connects glycolysis to the citric acid cycle (Krebs cycle). During the process of pyruvate oxidation, which occurs after glycolysis, pyruvate produced from glucose is converted into acetyl-CoA. This reaction is essential because acetyl-CoA serves as a substrate that enters the citric acid cycle, where it undergoes further oxidation to produce energy in the form of ATP, NADH, and FADH2.

The presence of coenzyme A is vital in this transformation because it ensures that the acetyl group, derived from the breakdown of carbohydrates, fats, and proteins, is properly activated and transported into the cycle for energy production. Thus, without coenzyme A, the conversion of pyruvate to acetyl-CoA would be impaired, leading to a decrease in the overall efficiency of cellular respiration and energy production.