What series of reactions take place during carbohydrate metabolism?

The correct choice accurately captures the major metabolic pathways involved in carbohydrate metabolism. The series of reactions begins with glycolysis, where glucose is broken down in the cytoplasm to produce pyruvate while generating a small amount of ATP and NADH. Following glycolysis, pyruvate enters the mitochondria and undergoes conversion into acetyl-CoA, which then enters the citric acid cycle (also known as the Krebs cycle or TCA cycle).

During the citric acid cycle, acetyl-CoA is further oxidized, leading to the production of additional NADH and FADH2, which are crucial electron carriers. The final step involves the electron transport system (also referred to as the electron transport chain), where the high-energy electrons from NADH and FADH2 are transferred through a series of proteins in the inner mitochondrial membrane. This process creates a proton gradient that ultimately drives the production of ATP through oxidative phosphorylation.

The other options include elements of carbohydrate metabolism but do not comprehensively cover the series of reactions as clearly as the selected choice. Glycogenesis, for example, pertains to the synthesis of glycogen, while gluconeogenesis involves the production of glucose from non-carbohydrate sources, but these are not central to the