Final answer:
Glycosaminoglycans (GAGs) are negatively charged polysaccharides that form large linear chains, which are a crucial component of proteoglycans in the extracellular matrix, playing key roles in the structure and function of connective tissues and in cell processes.
Step-by-step explanation:
Glycosaminoglycans (GAGs) are large linear polysaccharides that are negatively charged due to the presence of sulfate and uronic acid groups. They are a component of proteoglycans, which consist of a protein core covalently linked to one or more GAG chains. These structures are part of the extracellular matrix and contribute to its physical properties, such as resistance to compression and hydration. GAGs are involved in various biological processes, including cell signaling, and play a critical role in the structure and function of connective tissues.
GAGs also contribute to the formation of the glycocalyx, which is a layer of carbohydrates including glycoproteins and glycolipids that coats the surface of cells. This glycocalyx is vital for cell recognition, immune defense, and organ transplantation compatibility. In contrast, mucopolysaccharidoses are a group of metabolic disorders caused by the accumulation of GAGs due to enzyme deficiencies, leading to various health issues.