Biochem L5R

Question 1

what is the Extracellular matrix ( location, function) and how is it maintaned?

Answer 1

Main componenets of Extra. Matrix are

• Collogens Elastic fibers: provide tensile strength of the tissue
• Proteoglycans provide the resistance of the tissue.
• Hyaluronan: mediate adhesive interactions between other cells and matrix molecules.
• glycoproteins:……..

Maintenance

-dynamic interaction between cell and EM maintain function of tissue

• Resident cells Make the extracellular matrix
• cells connect to EM through cell surface receptors
• which allows cells to sense changes in EM
• Cell responsible to restore integrity in tissue damage arises

Question 2

When can remodeling/building the EM happen? what is used to control the remodeling process, EM.

Answer 2

Cells can degrade/remake EM during:

• Tissue differentiation( matrix composition changes)
• Cell migration ( cells moving through matrix
• cells secrete matrix Metalloprotienases MMPs,zn2+ degrade matrix protiens.
• MMPs is controlled by TIMPs (Tissue inhibitors of metalloprotenases) secreted by cell.

*cancer cells secrete large amounts of MMPs to invade surrounding tissue.

Answer 3

Collagen: main fibrillar protiens in connective tissues.

-Triple helical structure,

Collagen chain made of procollagen which contain propeptides, removed extracellularly after 3 procoll. are assembled into a triple helical structure.

Major groups:

1.Fibril forming: I. skin,bone,tendon,blood vessels cornea

II. Cartilage, intervertebral disk,vitreous body

III.Blood Vessels, fetal Skin

2.Network forming: IV.Basement membrane

3.Fibril-associated