So since we're on the subject of polysaccharides, let's focus on a specific group of polysaccharides that exist inside our body that plays a very important role, as we'll see in just a moment. And this group of polysaccharides is known as glycosaminoglycans. So what exactly is a glycosaminoglycan? Well, a glycosaminoglycan is a special type of polysaccharide that consists of repeating disaccharide units. So we have two sugars that repeat again and again and again. Now, one of these sugars is an amino sugar.