Final answer:
Proteoglycans are macromolecules composed of polysaccharide chains called glycosaminoglycans (GAGs), which are linked to proteins. They form gels that help hold cells and tissues together, lubricate joints, and contribute to the rubbery texture of cartilage. Proteoglycans attract and trap moisture to create a viscous matrix.
Step-by-step explanation:
Proteoglycans are macromolecules composed of polysaccharide chains called glycosaminoglycans (GAGs), which are covalently linked to proteins. They form gels that help hold cells and tissues together, lubricate joints, and contribute to the rubbery texture of cartilage. Proteoglycans attract and trap moisture, creating a viscous, colorless matrix known as ground substance.