Extracellular environment

Question 1

Where is type I collagen found

Answer 1

• bone
• skin
• dentin
• scar tissue

Question 2

Where is type II collagen found

Answer 2

• Cartilage
• Vitreous body
• nucleus pulposus

Question 3

where is type III collagen found

Answer 3

• blood vessels
• skin
• uterus
• embryonic/fetal tissue
• granulation tissue
• Reticular fibers

Question 4

Where is type IV collagen found

Answer 4

Basement membrane

Question 5

What are the learning tools for types of collagen

Answer 5

“SCAB”

• S: skin
• C: Cartilage
• A: Arteries
• B: basement membrane

bONE: type 1

“a STRONG, SLIPPERY, STRETCHY BM”

Question 6

What are the 2 common structures in preprocollagen alpha chains

Answer 6

• glycine-proline-X

- glycine-X-hydroxyproline

Question 7

In the synthesis of collagen, the hydroxylation of lysine and proline requires what

Answer 7

vitamin C

Question 8

In the synthesis of collagen, what need to happen to the hydroxylated lysine to make procollagen (triple helix of alpha chains)

Answer 8

glycosylation

Question 9

What happens to procollagen?

Answer 9

• exocytosis

- cleavage of terminal ends —> tropocollagen

Question 10

what happens to tropocollagen

Answer 10

-covalent crosslink to make collagen fibrils

Question 11

Osteogenesis imperfecta (OI) type I is deficiency of what

Answer 11

type I collagen

Question 12

Clinical features of OI type I

Answer 12

• Multiple fractures, limb deformities
• Blue sclerae
• hearing loss
• Dental abnormalities

Question 13

describe OI type II

Answer 13

Death in utero or in the neonatal period (“perinatal lethal OI”)

Question 14

Describe Classical Ehlers-Danlos syndrome (EDS)

Answer 14

• affects mainly TYPE 4 and type 1 collagen

- hyperextensible skin and joint hypermobility

Question 15

Describe hypermobility EDS

Answer 15

joint hypermobility WITHOUT hyperextensible skin

Question 16

Describe vascular EDS

Answer 16

• Defect in synthesis of TYPE 3 collagen

- Arterial rupture, hemorrhages, easy bruising, intracranial aneurysms

Question 17

Alport syndrome is defect of what

Answer 17

type 4 collagen

Question 18

Clinical features of Alport

Answer 18

-nephritis and kidney failure
-Hearing loss
-eye problems (e.g. cataracts, lenticonus)
“Can’t see, can’t pee, can’t hear high C”

Question 19

Defect in fibrillin (a component of elastin)

Answer 19

Marfan syndrome

Question 20

What amino acids make up elastin

Answer 20

Proline and glycine like collagen but NOT hydroxylated

Question 21

clinical features of Marfan syndrome

Answer 21

• hyperelastic joints
• disorders of heart valves and aorta
• Tall stature
• Long arms and legs; long fingers (“arachnodactyly”)
• Pectus carinatum (anterior protrusion of the sternum)