Carbohydrates have a lot to do with cellular respiration. A carbohydrate is a molecular compound that consists of the elements carbon, hydrogen, and oxygen. The popular carbohydrate of choice in cellular respiration is a simple sugar, glucose, that has the chemical formula of C6H12O6. Glucose is obtained from the digestive system breaking down the food you eat into a liquid form called chyme, then absorbing the glucose from it as it processes in the small intestine. Glycolysis is a process that takes glucose and converts it to pyruvate. The energy obtained by splitting the glucose molecule apart is converted into the high energy compounds ATP and NADP. Cellular respiration is the process by which this all happens, taking glucose and oxidizing it to obtain energy in the form of ATP, and producing carbon dioxide and water as waste products.