Final answer:
The citric acid cycle follows glycolysis in cellular respiration, oxidizing acetyl CoA to produce NADH and FADH2, which then donate electrons to the electron transport chain during oxidative phosphorylation. This process is coupled with chemiosmosis to produce ATP in the mitochondrion.
Step-by-step explanation:
The citric acid cycle, also known as the Krebs cycle or the tricarboxylic acid (TCA) cycle, is a crucial metabolic pathway that operates in the mitochondrial matrix of cells. Its primary role is the oxidation of acetyl groups derived from carbohydrates, fats, and proteins for the production of energy. Each turn of the cycle reduces NAD+ to NADH and FAD to FADH2, which are then utilized in oxidative phosphorylation to generate ATP, the main energy currency of the cell.
In the grand scheme of cellular respiration, the citric acid cycle follows glycolysis, which is the process of breaking down glucose into two molecules of pyruvate. These pyruvate molecules are further oxidized to acetyl CoA, which then enters the citric acid cycle. After glycolysis and the citric acid cycle, oxidative phosphorylation takes place. Here, NADH and FADH2, produced during earlier stages, donate their electrons to the electron transport chain. This process couples with chemiosmosis to produce ATP through a flow of protons across the mitochondrial membrane, ultimately leading to the synthesis of ATP by ATP synthase.