collagen synthesis

Question 1

What is the most abundant human protein ?

Answer 1

collagen

Question 2

What do different collagen types form ?

Answer 2

• fibrils
• fibres
• sheets (e.g. type IV)
• anchors

Question 3

How does RER help cells make collagen ?

Answer 3

• synthesis of pre-procollagen alpha-chains (glycine every 3rd residue allows helical conformation)
• Vitamin C-dependent hydroxylation of prolyl and lysyl residues
• assembly of triple helix to form procollagen

Question 4

How does golgi help cells make collagen ?

Answer 4

packing into secretory vesicles

Question 5

How does cell membrane help cells make collagen ?

Answer 5

constitutive exocytosis

Question 6

How does extracellular environment help cells make collagen ?

Answer 6

• non-helical terminal peptides cleaved
• collagen molecules assemble into fibrils

Question 7

each collagen subunit is approx :
1. long ?
2. wide ?

Answer 7

1. 300 nm
2. 1.5 nm

Question 8

Each collagen fibril is composed of …1.. with a ..2. banding which repeats every 67 nm

Answer 8

1. staggered collagen molecules
2. periodic

Question 9

Fibrils assemble into ..1… and these can assemble into …2…

Answer 9

1. fibres
2. larger bundles

Question 10

Type I collagen:
1. % of all collagen ?
2. fibrils …….
3. e.g. ….
4. …. componenet of bone

Answer 10

1. 90
2. aggregate into fibres and fibre bundles
3. tendons, capsules of organs and dermis
4. organic

Question 11

Type II collagen:
1. Fibrils DON’T form …
2. therefore form ……
3. present in ….. & ….. cartilage

Answer 11

1. fibres
2. very fine mesh
3. hyaline & elastic

Question 12

Type III collagen:
1. Fibrils form …. NOT …,.
2.Where found around ?
3.Where found within ? called what ?
4.Also found in … particularly ….

Answer 12

1. branching fibres , bundles
2. muscle and nerve cells
3. lymphatic tissues and organs , reticulin
4. skin , papillary dermis

Question 13

Type IV collagen:
1. …form
2. present in ….. of … membrane

Answer 13

1. unique (sheet)
2. basal lamina, basement

Question 14

Type VII collagen ?

Answer 14

anchors basal lamina to underlying reticular lamina