Explain how the fixed negative charge on cartilage is responsible for about 50% of the compressive stiffness of the tissue (or resistance to deformation under a compressive load).

Explain how the fixed negative charge on cartilage is responsible for about 50% of the
compressive stiffness of the tissue (or resistance to deformation under a compressive
load). Your explanation should include a definition and discussion of how the
compressive stiffness of cartilage is influenced by (a) chemical expansion stress and (b)
Donnan osmotic pressure. It should also explain the roles of proteoglycan and collagen in
these phenomenon.