ABSTRACT
Carbohydrates are organic molecules made up of carbon, hydrogen and oxygen. They are consumed in the diet as either simple sugars or complex sugars. Complex sugars are essentially simple sugars assembled into chains for ease of storage, or to form structures. The main pathways in glucose metabolism are: glycolysis, gluconeogenesis, glycogenesis and glycogenolysis. Glucose is stored as the multi-branched polysaccharide glycogen, primarily in the liver and muscles. Glycogenesis occurs when glucose and Adenosine triphosphate (ATP) are present in relatively high amounts as it uses up one ATP molecule for every glucose molecule incorporated into the chain. Glycogen stored in the liver is broken down by glycolysis, which releases glucose into the blood for utilisation by other cells, while that present in the skeletal muscle provides an immediate energy source for muscle contraction. The aim of glycolysis is to split the 6-carbon sugar glucose into two molecules of the 3-carbon sugar pyruvate.
