Cellular respiration is a vital process through which cells generate energy from glucose, producing adenosine triphosphate (ATP), the primary energy currency of the cell. This process begins with glycolysis, which occurs in the cytosol and breaks down glucose into pyruvate, yielding a small amount of ATP and NADH. Pyruvate then undergoes a transition reaction in the mitochondria to form acetyl CoA, which enters the Krebs cycle. This cycle, also known as the citric acid cycle, processes acetyl CoA to produce additional NADH, FADH₂, and ATP, while releasing carbon dioxide. The final stage, oxidative phosphorylation, involves the electron transport chain and ATP synthase, which utilize the high-energy electrons from NADH and FADH₂ to generate the majority of the cell’s ATP by creating a proton gradient across the inner mitochondrial membrane. This gradient drives ATP synthesis as protons flow back into the mitochondrial matrix. Cellular respiration is essential for both prokaryotic and eukaryotic cells, though it occurs in different locations depending on the cell type. Overall, cellular respiration is a complex and efficient way for cells to convert glucose into usable energy, with ATP playing a central role in storing and transferring this energy for various cellular functions.