ECM-COLLAGEN

Question 1

What does collagen comprise of

Answer 1

three alpha chains forming a triple helix

Question 2

describe type 1 collagen

Answer 2

Type I collagen has chains from two different genes - its composition is [alpha1 (I)]2 ( alpha2(I)]. ( 2 alpha ones and one alpha 2 chain)

Question 3

describe type ii and iii collagen

Answer 3

Types II and III collagen have only one chain type – their compositions are, therefore, [alpha 1 (II)]3 and [alpha 1 (III)]3

Question 4

collagen characteristic is gl-x-y. What is typically x and y?

Answer 4

x=proline, y=hydroxyproline

Question 5

Outline the biosynthesis of fibrillar collagen

Answer 5

1) synthesis of the pro alpha chain
2) hydroxylation of select prolines and lysine
3) Glycosylation of select hydroxylysines
4) self assembly of three pro alpha chains
5) pro collagen triple helix forms
6) secretion
7) cleavage of propeptides
8) self assembly into fibrils
9) aggregation of fibrils to form collagen fibre

Question 6

Name the non-collagenous domains of newly synthesised collagen

Answer 6

N-terminal (left) and C terminal (right) propertides

Question 7

What happens to the N-terminal and C terminal after secretion for fibrillar collagens

Answer 7

They remain attached

Question 8

What happens to the N-terminal and C terminal after secretion for most collagens

Answer 8

They are removed

Question 9

What 2 effects does cross linking have on collagen

Answer 9

provides tensile strength, provides stability

Question 10

what 2 residues are involved in cross linking

Answer 10

lysine and hydroxylysine

Question 11

Explain how vitamin C deficiency can cause scurvy (4 marks)

Answer 11

Prolyl and lysyl hydroxylases require Fe2+ and vitamin C

Contributes to interchain hydrogen bond formation.

Lysine and hydroxylysine are also modified in the formation of covalent crosslinkages. This takes place only after the collagen has been secreted.

Vitamin C-deficiency results in underhydroxylated collagens, with dramatic consequences for tissue stability (scurvy).

Question 12

What is Ehlers-Danlos syndrome? (EDS)

Answer 12

are a group of inherited connective tissue disorders whose symptoms include stretchy skin and loose joints

Question 13

Several disorders arise due to mutations in collagen, which negatively affect: (list 3)

Answer 13

.collagen production
.collagen structure
.collagen processing

Question 14

what is type IV collagen

Answer 14

Network forming collagen present in all basement membrane

Question 15

what are types IX and XII collagen

Answer 15

fibril-associated collagen which associate with fibrillar collagens regulating organisation of collagen fibres