Extracellular Matrix Proteins

Question 1

ECM proteins providing structural support

Answer 1

Collagen

Question 2

ECM proteins providing elasticity

Answer 2

Elastin, fibrin

Question 3

Proteins providing adhesion between structural matrix proteins

Answer 3

Laminin, fibronectin

Question 4

ECM proteins providing mechanical support

Answer 4

Proteoglycans

Question 5

ECM proteins providing anchoring and communication

Answer 5

Integrins

Question 6

Where is elastin commonly found?

Answer 6

Forms elastic fibers in smooth muscle and lung

Question 7

Elastin is synthesized as a ______ precursor

Answer 7

Tropoelastin

Question 8

Elastin has alternating ______ and ______ domains

Answer 8

Hydrophilic and hydrophobic

Question 9

Function of laminin

Answer 9

Cross links proteins in the basal laminae

Question 10

Laminin structure

Answer 10

Heterotrimeric, triple helix, globular N extensions

Question 11

Function of proteoglycans

Answer 11

Forms gel that provides mechanical support

Question 12

Proteoglycans are extensively _______

Answer 12

Glycosylated

Question 13

Carbs are usually attached to the core protein of proteoglycans via ____ or ______

Answer 13

Ser or Thr

Question 14

Glycosaminoglycans consist of repeating ______

Answer 14

Disaccharides

Question 15

Polysaccharide chains are called

Answer 15

Glycosaminoglycans

Question 16

Integrins attach to adhesion proteins such as

Answer 16

Fibronectin

Question 17

All integrins have ___ subunits

Answer 17

2

Question 18

Integrins mediate _______ cell signaling

Answer 18

Two way

Question 19

Over 90% of human collagen is types ______

Answer 19

I-III

Question 20

All collagens contain _____ polypeptide chains and have at least one ___ ______ ______

Answer 20

3, triple helix domain

Question 21

Type I collagen

Answer 21

Widely distributed, major component of tendon and bone

Question 22

Type II

Answer 22

Cartilage, cornea, vitreous fluid

Question 23

Type III

Answer 23

Loose CT, extensible tissues

Question 24

Collagen type I chain composition

Answer 24

[α1(I)]2 α2(I)

Skin and bone

Question 25

Collagen type II chain composition

Answer 25

α1(II)3 Cartilage

Question 26

Collagen type III chain composition

Answer 26

α1(III)3 Blood vessels

Question 27

Each collagen chain has _____ amino acids

Answer 27

1000

Question 28

In collagen chains, every third residue is ___

Answer 28

Gly

Question 29

Collagen contains about 20% ______ and _____\\

Answer 29

Proline and hydroxyproline

Question 30

Each collagen chain forms a _____-like _____-handed helix

Answer 30

Proline, left

Question 31

Collagen chains are stabilized by

Answer 31

Steric repulsión of pyrrolidone rings

Question 32

Collagen helix is essentially a ________ structure

Answer 32

Tertiary

Question 33

Collagen helices are stabilized by

Answer 33

Interchain hydrogen bonds

Question 34

Vitamin C is required for what process?

Answer 34

Hydroxylation of proline and lysine residues in collagen chains

Question 35

Procollagen is the precursor for _____ collagens

Answer 35

Fibrillar

Question 36

How does procollagen become mature collagen?

Answer 36

Ends are cleaved to make tropocollagen Tropocollagen is packed into collagen fibrils, which are then layered into mature collagen

Question 37

Sulfide bonds at the _-terminal assist with helix formation

Answer 37

C

Question 38

Collagen stability depends on cross links initiated by ____ _____

Answer 38

Lysyl oxidase

Question 39

Lysyl oxidase converts lysine or hydroxylysine into ______

Answer 39

Allysine

Question 40

Cross linking is an ENZYMATIC/NONENZYMATIC reaction between _____ and _____ groups

Answer 40

Non-enzymatic, lysyl and allysyl

Question 41

At what point during collagen synthesis is it secreted from the cell?

Answer 41

After the folding of the triple helix

Question 42

What type of collagen forms networks/mesh?

Answer 42

Type IV

Question 43

Scurvy is a disruption of what process?

Answer 43

Hydroxylation of proline and lysine, which in turn reduces interchain H bonding

Question 44

What clinical marker is indicative of collagen disorders?

Answer 44

Blue sclera

Question 45

Ehlers-Danlos manifests as

Answer 45

Loose skin and hyper flexible joints

Question 46

Substitutions of ____ in the α1(I) chain of collagen I can lead to what disease?

Answer 46

Glycine, osteogenesis imperfecta