The process through which energy is released from glucose is known as cellular respiration. This metabolic pathway occurs in several stages: glycolysis, the citric acid cycle, and oxidative phosphorylation. Initially, glucose is broken down in glycolysis, producing pyruvate and a small amount of ATP. The pyruvate then enters the mitochondria, where it undergoes further breakdown in the citric acid cycle, generating electron carriers. These carriers donate electrons during oxidative phosphorylation, leading to the production of a significant amount of ATP, providing energy for cellular activities.