Fibrous Proteins

Question 1

What is purpose of collagen?

Answer 1

Provides body structure by protecting and supporting soft tissues

Question 2

What is the mutation that causes Ehlers-Daners syndrome?

Answer 2

Identifiable mutation in COL5A1 or COL5A2, which encodes the type V collagen

Question 3

What gender does EDS disproportionally affect?

Answer 3

Women

Question 4

What is osteogenesis imperfecta

Answer 4

Brittle bone disease–numerous fractures and bone deformity

Question 5

What is the mutation that causes in Osteogenesis imperfecta

Answer 5

Mutation of Glycine in the Gly-X-Y triplet to Ala, Val, Ser

Question 6

What is the role of collagen in bone formation?

Answer 6

Organic phase–collagen
Inorganic phase– Hydroxylapatite

Question 7

What are the four molecules that make up collagen?

Answer 7

Glycine, Alanine, Hydroxylysine, Proline and 4-Hydroxyproline

Question 8

How does the collagen triple helix stabilize?

Answer 8

Inter-chain H bonding between a Glycine residue on one chain and a Proline residue of another chain within the helix

Question 9

What kind of bond stabilizes the triple helix(tropocollagen)

Answer 9

Inter-strand disulfide bonds

Question 10

What is the purpose of the procollagen N-terminal polypeptide?

Answer 10

It is the feedback control of net collagen synthesis and regulates growth factor activity in extracellular matrix

Question 11

Why is hydroxylation of lysine important?

Answer 11

Sugar attachment–as a carbohydrate can stabilize the collagen

Question 12

Why is hydroxylation of proline important?

Answer 12

Two reasons: 1) Triple helix stability 2) Fibril(mini-Fiber) Stability

Question 13

Why is ascorbate essential?

Answer 13

serves as a cofactor for lysine and proline hydroxylases.(Also known as Vitamin C)

Question 14

What is the disease that is due to a deficiency of Vitamin C?

Answer 14

Scurvy

Question 15

Deficiency in Vitamin C prevents what chemical process?

Answer 15

Proline Hydroxylation

Question 16

What enzyme converts lysine to allysine?

Answer 16

Lysyl Oxidase

Question 17

Why is it important to form crosslinks in collagen?

Answer 17

Mainly for strength and stability throughout the body.

Question 18

Which two amino acids form crosslinks in collagen?

Answer 18

Lysine and Histidine

Question 19

T/F: There are disulfide cross links in mature collagen

Answer 19

FALSE

Question 20

T/F: Elastin is highly hydrophobic

Answer 20

TRUE

Question 21

What is desmosine made up of?

Answer 21

4 Lysine residues

Question 22

Mutations in fibrillin gene cause what syndrome?

Answer 22

Marfan’s

Question 23

Which has more entropy, the relaxed state or the stretched state?

Answer 23

Relaxed because there are different ways of arranging the polymer chain

Question 24

What is Supravalvular Aortic Stenosis caused by?

Answer 24

SVAS is due to mutations in elastin or decrease of elastin production

Question 25

What are some problems associated with Williams Syndrome?

Answer 25

Heart and Blood Vessel defects(Hypertension, Hypercalcemia)

Question 26

What do fibulins help assemble?

Answer 26

Tropoelastin

Question 27

What do fibulins facilitate?

Answer 27

Binding of Lysyl oxidase to the elastin fibril