Cellular respiration is a process that converts glucose into ATP, which is used by cells for energy. The stages of cellular respiration include: Glycolysis: This occurs in the cytoplasm and breaks down one molecule of glucose (6-carbon) into two molecules of pyruvate (3-carbon), producing 2 ATP and 2 NADH. Krebs Cycle (Citric Acid Cycle): This occurs in the mitochondria. Each pyruvate is further broken down, releasing carbon dioxide, producing NADH, FADH2, and a small amount of ATP. Oxidative Phosphorylation (Electron Transport Chain): This occurs in the inner mitochondrial membrane. NADH and FADH2 donate electrons to the electron transport chain, which ultimately results in the production of a large amount of ATP and water. Oxygen acts as the final electron acceptor.