Proteoglycans

Question 1

what are the sugar units of the GAGs?

Answer 1

amino sugar - either N-acetyl glucosamine or N-acetylgalactosamine

acidic sugar- glucoronic acid or idurinic acid

Question 2

Which type of GAG is this?:

• most abundant
• found in cartilage, tendons, ligaments, and aorta
• form proteogylcan aggregates
• strong association with collagen
• formation of bone, cartilage, cornea

Answer 2

Chondroitin 4- and 6-sulfates

Question 3

Which type of GAG is this?:

• most heterogeneous
• type II is found in loose connective tissue; type 1 is in the cornea
• transparency of cornea

Answer 3

keratan sulfates

Question 4

Which type of GAG is this?:

• unsulfated
• also found in bacteria
• serves as lubricant and shock absorber
• found in synovial fluid of joints, vitreous humor, umbilical cord
• function in embryognesis, morphognesis, wound healing

Answer 4

hyaluronic acid

Question 5

Which type of GAG is this?:

• helps attachment of LDL to endothelial cells
• found in skin, blood vessels, heart valves
• transparency of cornea

Answer 5

dermatan sulfate

Question 6

Which type of GAG is this?:

• intracellular component of mast cells in liver, lungs, skin
• anticoagulant

Answer 6

heparin

Question 7

Which type of GAG is this?:

• basement membrane
• helps attachment of lioprotein lipase

Answer 7

heparan sulfate

Question 8

• chronic, progressive, multi-system lysosomal disorder
• normal at birth
• detected by partially degraded GAG in urine

Answer 8

mucopolysaccharidoses/lysosomal storage diseases

Question 9

what are the 3 ways an MPS disorder can present?

Answer 9

• as a dysmorphic syndrome
• with learning difficulties, behavioral disturbances, and dementia
• as severe bone dysplasia

Question 10

This normally helps in cell migration; tumor cells secrete it in large amounts, and it allows the cels to migrate through the ECM (metastasis)

Answer 10

hyluronic acid

Question 11

This normaly helps the cell adhere to each other; tumors cells have less of it at their surfaces and hence lack adhesiveness so they migrate (metastasis)

Answer 11

heparan sulfate

Question 12

this binds to low density lipoproteins (LDLs) and plays a role in atherosclerosis

Answer 12

dermatan sulfate

Question 13

what changes atribute to osteoarthritis?

Answer 13

chondrotin sulfate decreases, keratan sulfate and hyaluronic acid increase