Collagen/Elastin

Question 1

Which is the main structural protein of the extracellular matrix?

Answer 1

Collagen

Question 2

Collagen type 1 can be found in

Answer 2

Bone, skin, tendons

Question 3

Collagen type 2 can be found in

Answer 3

Cartilage

Question 4

Collagen type 3 can be found in

Answer 4

Blood vessels, granulation tissue, uterus

Question 5

Collagen type 4 can be found in

Answer 5

Basement Membrane

Question 6

Collagen structure

Answer 6

Three alpha chains linked by disulfide bonds (also hydrogen bonds)

Question 7

Steps in Collagen synthesis (6 steps)

Answer 7

1. Synthesis of individual alpha chains
2. Hydroxylation of Proline and Lysine
3. Glycosilation of hydroxyproline = Procollagen
4. Exocytosis of procollagen
5. Cleavage of terminal regions
6. Cross-linking between collagen molecules

Question 8

Which step of collagen synthesis needs Vit C?

Answer 8

Hydroxilation of proline and lysine

Question 9

Hydroxilation of proline and lysine needs ____________

Answer 9

Vitamin C

Question 10

Osteogenesis imperfecta affects which type of Collagen?

Answer 10

Type 1

Question 11

Clinical features of Osteogenesis imperfecta

Answer 11

Bone fragility + Blue sclera + Dental problem/Hearing loss

Question 12

Osteogenesis imperfecta inheritance pattern

Answer 12

Autosomal Dominant

Question 13

Ehlers Danlos affects which type of Collagen

Answer 13

Type 3 (Also Type 5)

Question 14

Ehlers Danhlos Clinical features

Answer 14

Hypermobile joints and Hyperextensible skin
Type 5: More vascular compromise

Question 15

Merkes Syndrome is caused by

Answer 15

Poor copper absorption = Decreased collagen synthesis

Question 16

Merkes Syndrome clinical features

Answer 16

Brittle hair + Cognitive impairment

Question 17

What is elastin?

Answer 17

Large and very stretchy protein commonly found in connective tissue

Question 18

Sites where you can find Elastin

Answer 18

Skin, blood vessels, lungs and Ligament flava

Question 19

What action does Alpa-1- Antitrypsin do?

Answer 19

Increases elastase activity = Decrease elastin

Question 20

Syndrome characterized by defective fibrillin?

Answer 20

Marfan Syndrome

Question 21

Patient with Marfanoid Habitus + Pectus carinatum + Aortic incompetence. Diagnosis

Answer 21

Marfan Syndrome

Question 22

Marfan syndrome pathogenesis:

Answer 22

Defective fibrillin (Decreased production of sheath around elastin)

Question 23

Lens abnormality associated to Marfan Syndrome

Answer 23

Superotemporal/Temporal Lens subluxation

Question 24

Marfan Syndrome inheritance pattern

Answer 24

Autosomal dominant