CB18 Proteins of the extracellular matrix

Question 1

Describe the major proteins of the extracellular matrix

Answer 1

• Collagen
• Elastin
• Fibronectin
  laminin
  Tenascin

Question 2

Describe now collagen fibres are assembled

Answer 2

3 polypeptide chain
↓
Collagen molecule
↓
Collagen fibrils
↓
Collagen fibre

Question 3

Describe the role of proteoglycans in cartilage

Answer 3

GAGs are hydrophilic their negative charge attracts cations such as Na+, causing large amounts of water to be sucked into the matrix.

This enables the matrix to withstand compressive forces e.g. Cartilage of stifle joint

Question 4

How is elastin suited to stretch & relax

Answer 4

Molecules are joined together by covalent bonds to generate a cross-linked network, so that the entire assembly can stretch & recoil