Final answer:
Glycogen is the main storage form of glucose in animals, highly concentrated in the liver and muscles. It is broken down through glycogenolysis to maintain blood glucose levels and provide energy during exercise. Liver and muscle tissues store glycogen to ensure glucose availability, with muscles storing around 70% of total body glycogen.
Step-by-step explanation:
Glycogen is a critical energy storage molecule in animals, including humans. It is a polymer made up of glucose monomers and is structurally similar to starch in plants. This polysaccharide is principally stored in the liver and muscle tissue. The liver's glycogen stores are essential for maintaining blood glucose levels, while muscle glycogen is crucial for providing energy during vigorous activities such as exercise.
The processes of glycogenolysis (the breakdown of glycogen to release glucose) and glycogenesis (the formation of glycogen from glucose) are essential for energy regulation, especially during fasting or increased energy demands. Glycogen transformation to glucose 1-phosphate (G-1-P) and then to glucose 6-phosphate (G-6-P) allows it to enter the glycolytic pathway and be used for ATP production.
While the percentage of glycogen in liver cells is higher by weight, skeletal muscles, due to their mass, store a greater total quantity of glycogen, accounting for approximately 70% of the total glycogen in the body.