1.14 ECM II - Matrix Proteins

Question 0

Name the 2 Adhesion proteins in the ECM

Answer 0

Fibronectin

Laminin

Question 1

Name the two structural proteins in the ECM

Answer 1

Collagen

Elastin

Question 2

Collagen is synthesized and secreted by

Answer 2

Fibroblasts

Question 3

Describe the unusual primary structure of the alpha-collagen peptide

Answer 3

Few amino acids that are repetitive

1. Glycine
2. Proline
3. Hydroxyproline and Hydroxylysine

Question 4

T or F, All collagen types are constructed from 3 left handed helical peptide chains

Answer 4

True

Question 5

Which type of collagen accounts for 90% of the body’s collagen

Answer 5

Type I

Question 6

4 steps of collagen post translational modifications

Answer 6

Hydroxylation of Proline and Lysine residues
Glycosylation of Hydroxyl-lysine
Cleavage of N and C terminal propeptides (topocollagen)
Cross-linking of lysine residues to form fiber

Question 7

Which step in collagen modification requires Ascorbate or Vitamin C?

Answer 7

Hydroxylation of proline and lysine residues

Question 8

What enzyme helps cross-link lysine residues when forming the fiber

Answer 8

Lysyl Oxidase

Question 9

What are the three difference of non fibrillar collagen and fibrillar collagen

Answer 9

1. lack glycine in primary structure for tight collagen helix
2. not cleaved after secretion so they retain propeptides
3. Do not aggregate with one another to form fibrils

Question 10

What is the 3 step process of collagen degradation

Answer 10

1. Enzyme binding
2. Unwinding of triple helix
3. Cleavage of collagen peptides

Question 11

Two enzymes available for Collage degradation

Answer 11

Matrix Metalloproteinases

Cathepsins

Question 12

Which disorder is characterized by a decrease in Type I Collagen synthesis and are manifested by long bone fractures prior to maturity

Answer 12

Osteogenesis Imperfecta I