Glycosaminoglycans (GAGs) are long, unbranched carbohydrates made up of repeating disaccharide units. They are found in various tissues throughout the body, playing essential roles in maintaining the structure and function of connective tissues. GAGs are important for hydration and elasticity, contributing to the properties of cartilage, skin, and blood vessels. These molecules are negatively charged and attract water, which helps to create a gel-like consistency in the extracellular matrix. Common types of GAGs include hyaluronic acid, chondroitin sulfate, and heparin. Their unique properties make them vital for processes such as cell signaling, tissue repair, and inflammation regulation.