And this is a very important distinction because other sources of energy, for instance fatty acids, depend on oxygen. But in the case of glycogen, we can actually break down glycogen into glucose and produce energy without using oxygen. So glycogen can be stored in two types of cells. So we have the liver cells and skeleton muscle cells and the glycogen molecules, the glycogen polymers are actually stored in these tiny granules found throughout the cytoplasm of the liver and the skeleton muscle cells. So this is basically what glycogen actually looks like. And as I mentioned before, the liver cells use the glycogen primarily to actually regulate and maintain the proper levels of glucose inside our blood, while the skeleton muscle cells actually use the glycogen to break it down to glucose, to use it as a rapid energy source for sudden and strain use activity.