What characteristic of chondroitin sulfate contributes to its gel-like properties and volume increase in solution?

• A. Adhesion to collagen
• B. Covalent bonding with core protein
• C. Presence of surface negative charges
• D. High-molecular-weight polymer formation

Answer: (C)

Chondroitin sulfate possesses a significant number of negatively charged sulfate and carboxyl groups, which are responsible for its gel-like properties and ability to absorb water. These surface negative charges lead to the repulsion between molecules, causing them to spread out and hold onto water molecules. This interaction increases the volume of the solution and contributes to the viscosity and gel-like consistency observed with chondroitin sulfate.

The presence of these negative charges not only aids in hydration but also plays a crucial role in the biochemical interactions with surrounding matrix components, which is essential for its function in cartilage and connective tissue. Thus, the characteristic of having surface negative charges is fundamental to its unique physical properties and biological function.