Carbohydrates: Catabolism of Carbohydrates for Energy Purposes Carbohydrates are a primary source of energy for the human body, providing fuel for cellular activities and physiological functions. The catabolism of carbohydrates involves a series of metabolic pathways that break down complex carbohydrates into simpler molecules, releasing energy that is stored in the form of adenosine triphosphate (ATP). This process, known as carbohydrate catabolism, includes glycolysis, the citric acid cycle (Krebs cycle),