Now the proteoglycan itself is a protein that contains a carbohydrate component. And usually in the extracellular matrix, proteoglycans are attached to molecules known as glycosaminoglycans. So these are found in connective tissue as well as are responsible for functioning in cell Adhesion. Now, what exactly is a glycos aminoglycan? Well, a glycosaminoglycan is basically some type of disaccharide repeating unit that contains an aminosugar derivative. And one common example of a glycos aminoglycan in the human body is a molecule known as heparin, which basically looks something like this.