Glucose is a simple carbohydrate that acts as a primary source of energy for many physiological functions. Through a four phase process called cellular respiration, the body can metabolize and use the energy found in glucose.
Glucose is broken down in the parenchymal cells and tissues of the liver.
Cellular respiration releases energy in the body but first requires the splitting of glucose into water and carbon dioxide.
Glycolysis is the first phase of breakdown in which glucose is broken into two molecules of pyruvate in the cytoplasm.
The second phase of glucose breakdown is the transition reaction. During this phase, carbon dioxide is removed and the pyruvate molecules are broken into a 2-carbon aceytl.
The citric acid cycle,also called the Krebb's cycle, is the third phase and occurs inside the mitochondria, the cell's powerhouse. A series of oxidation reactions produce NADH, FADH, and ADP.
The fourth phase of glucose breakdown is the electron transport system. For every two electrons that enter the system, three ATP are produced.
