Glycogen is a multi-branched polysaccharide of glucose that serves as a form of energy storage in animals and fungi. It is the primary storage form of glucose in the body, predominantly found in the liver and muscle tissues. Glycogen is highly soluble in water due to its branched structure, which allows for rapid mobilization of glucose when energy is needed. It is not soluble in alcohol or fats. Glycogen plays a crucial role in maintaining blood sugar levels and providing energy during physical activity. In the context of food, glycogen is not typically found in plant-based foods but is present in animal-derived products, such as meat and seafood. Its structure consists of glucose units linked by α(1→4) glycosidic bonds with branching via α(1→6) bonds approximately every 8 to 12 glucose units.