Glycogen

Definition

Glycogen is a multi-branched polysaccharide of glucose that serves as a form of energy storage in animals and fungi. It is primarily stored in the liver and muscle tissues, where it can be rapidly mobilized to meet sudden energy demands.

5 Must Know Facts For Your Next Test

1. Glycogen is synthesized through glycogenesis and broken down through glycogenolysis.
2. Liver glycogen helps maintain blood glucose levels, while muscle glycogen provides energy during physical activity.
3. It is highly branched, which allows for rapid release of glucose when needed.
4. Insulin promotes the synthesis of glycogen, whereas glucagon and epinephrine stimulate its breakdown.
5. Glycogen storage diseases are a group of metabolic disorders that affect glycogen synthesis or breakdown.

Review Questions

• What are the primary locations in the body where glycogen is stored?
• Which hormones regulate the synthesis and breakdown of glycogen?
• Describe the structural characteristic of glycogen that allows for quick mobilization of glucose.

Related terms

Glucose: A simple sugar that serves as a primary source of energy for cells and is a building block for carbohydrates like glycogen

Glycogenesis: The biochemical process by which glucose molecules are added to chains of glycogen for storage

Glycogenolysis: The breakdown of glycogen into glucose-1-phosphate and then into glucose to provide immediate energy