Cells convert glucose into ATP through a process called cellular respiration. This occurs in several stages: first, glycolysis breaks glucose down into pyruvate in the cytoplasm, producing a small amount of ATP. Then, in the presence of oxygen, pyruvate enters the mitochondria where it undergoes the Krebs cycle, generating electron carriers. Finally, the electron transport chain uses these carriers to produce a significant amount of ATP through oxidative phosphorylation. Overall, this process efficiently transforms the energy in glucose into usable energy in the form of ATP.