Difference Between Glucagon and Glycogen

Glucagon vs Glycogen

Every living organism needs utilization of storage compounds for their survival, when they are in lack of food. Therefore, for the future use, it is beneficial to store supplementary food as an utilizable form inside the body. For the plants, starch acts as a storage compound while, for the animals, it is glycogen. For the utilization of these storage compounds, every organism including human has their own mechanism. When considering the blood sugar controlling mechanism in human, mainly the activity of insulin and glucagon hormones is necessary. Though the activity is antagonistic, both of these hormones play an important role in regulation of blood sugar level.


Glucagon is a hormone which is secreted by alpha cells in the islets of Langerhans in pancreas. Considering its biochemical structure it is made up of a single polypeptide chain with 29 amino acids. The role of glucagon is to activate phosphorylase enzyme in the liver when the blood glucose concentration is lower than the default level thereby catalyses the conversion of glycogen to glucose. Not only that, glucagon increases the synthesis of glucose from non-carbohydrate sources.


Glycogen is the storage carbohydrate polymer in human and other animals. Actually, it is a branched chain polymer of α-D-glucose. Like starch in plants, glycogen also found within granules in animal cells. Under normal conditions, glycogen granules can be seen in well-fed liver and muscle cells but not in the brain and heart cells.

What is the difference between Glucagon and Glycogen?

• Glucagon is a hormone, and it is a form of polypeptide, whereas glycogen is a type of polysaccharide.

• Glucagon plays a vital role in regulating blood glucose concentration when it is lower than default level, but the glycogen is a form storage compound in human and other animals.

• Glucagon is synthesized by the alpha cells in the islets of Langerhans while glycogen is synthesized and stored in the liver.

• Glucagon helps to convert glycogen into glucose, when necessary.