The process by which glucose is broken down to release energy is known as cellular respiration. This multi-step process involves glycolysis, the Krebs cycle, and oxidative phosphorylation. During glycolysis, glucose is converted into pyruvate in the cytoplasm, while the Krebs cycle further oxidizes pyruvate inside the mitochondria, producing electron carriers such as NADH and FADH2. These carriers then enter the electron transport chain, where ATP is generated through oxidative phosphorylation, ultimately resulting in the production of water and carbon dioxide as byproducts, thus releasing energy for cellular functions.