Glucose is the main source of fuel for our cells. When the body doesn't need to use the glucose for energy, it stores it in the liver and muscles. This stored form of glucose is made up of many connected glucose molecules and is called glycogen.
What is glycogen a store of?
When we eat carbohydrates, our body changes it into a form of sugar called 'glucose' that can be used for energy. The glucose, in turn, is changed to Glycogen, a form of sugar that can be easily stored by our muscles and liver. It is the predominant storage form of glucose and carbohydrates in animals and humans.
Why is glucose stored as glycogen?
In animal cells, glucose is generally stored in the form of glycogen. This is done to not upset the osmotic balances in the cell. Glucose molecules are soluble in water and thus can cause the cell to become hypertonic. This will result in the entry of water molecules within the cells and cause it to lyse.