Extracellular matrix (deevska)

Question 1

4 major components of Extracellular matrix?

Answer 1

Collagen fibers- gives tissue tensile strength
Elastic fibers- elasticity to tissue
Proteoglycans and hyaluronic acid- gel like or slimy
Glycoproteins- glue holds fibers and cells together

Question 2

ECM components are very abundant in the eye. What are some parts of the eye that are involved?

Answer 2

Sclera, Cornea, Lens, vitreous humor, Bruch membrane

Question 3

What is the most abundant protein in the human body? Long, rigid structure in which 3 polypeptides are wound around one another in a rope like triple helix.

Answer 3

Collagen fibers

Question 4

Collagen fibers structure is rich in 2 amino acids, what are they?

Answer 4

Proline

Glycine (about every 3 amino acids)

Question 5

Hydroxylysine may be ___________ with glucose or galactose before the formation of the triple helix.

Answer 5

glycosylated

Question 6

__________ is required as a cofactor for the enzymes involved in hydroxylation of proline and lysine residues in collagen. Lack of this leads to what disease?

Answer 6

Vitamin C

Scurvy

Question 7

Lack of proline and lysine greatly decrease the tensile strength of the assembled fiber, how?

Answer 7

interchain H-bond formation is impaired which prevents formation of stable triple helix

Question 8

Cross linking occurs extracellularly by what enzyme?

Answer 8

Lysyl oxidase (cu containing enzyme)

Question 9

What disease is copper deficiency?

Answer 9

X-linked Menkes disease

Question 10

What disease is Copper overload?

Answer 10

wilson disease

Question 11

What is a defect in any synthetic steps?

Answer 11

Collagenopathies

Question 12

What disease leads to brittle hair (kinky hair disease) because of lack of copper?

Answer 12

Menkes syndrome (MNK)

Question 13

What disease is from too much copper in the body and has kayser-Fleischer rings in the eye?

Answer 13

Wilson’s disease

Question 14

What disease has brittle bones and two types where (Type 1 is less severe and Type 2 is fatal in utero or in neonatal disease)? Blue sclera and hearing loss also involved

Answer 14

Osteogenesis Imperfecta (OI)

Question 15

Ehlers-Danlos Syndrome has what characteristics?

Answer 15

defective collagen genes 
Leads to:
elastic skin
hypermobile joints
easy bleeding

Question 16

Elastic fibers have a composition of what?

Answer 16

Inner core of amorphous elastin

Question 17

She said this could be a question on test… But I didn’t hear the question… just the answer… on slide 12

Answer 17

Has very little post transcriptional modifications (hydroxyproline and hydroxylysine)

Question 18

INsoluble protein polymer synthesized from a precursor _________.

Answer 18

Tropoelastin

Question 19

Extensively interconnected, rubbery network that can stretch and bend in any direction when stressed, giving _____________ elasticity.

Answer 19

connective tissue

Question 20

What is the cause of Marfan’s syndrome?

Answer 20

mutations in the fibrillin-1 protein
rare dominantly inherited condition
pts are unusually tall with long spidery gingers and the lens is displaced

Question 21

What are large complexes of heteropolysaccharide chains associated with a small amount of protein.

Answer 21

Proteoglycans

Question 22

What are proteins with a variable but typically small amount of carbohydrate (2 to 10 sugar residues)

Answer 22

Glycoproteins

Question 23

Proteoglycans functions:

Answer 23

Produce a gel-like matrix
Form the basis of the body’s ground substance
Flexible support
etc…

Question 24

Large complexes of negatively charged heteropolysaccharide chains.
Unbranched
repeating dissaccharide units

Answer 24

Glycosaminoglycans

Question 25

GAGs have a strong (-) charge due to ______ groups and ______ groups.

Answer 25

carboxyl

sulfate

Question 26

What are the 6 classes of GAGs?

Answer 26

Chondroitin 4 and 6 sulfates
Keratan sulfates I and II- (I found in corneas)
Hyaluronic acid- animal and bacteria tissues
Dermatan sulfate- skin
Heparin- mast cells (anticoagulant)
Heparan sulfate- (same as heparin except acetylated) also extracellular GAG

Question 27

Be able to locate a specific GAG to a location in the human body…

Answer 27

slide 21

Question 28

Where is synthesis of core protein happening?

Answer 28

ER lumen –> Golgi where it is glycosylated by glycosyltransferases to form short carbohydrate linkage region

Question 29

Active transport mechanism that requires energy, cells engulf stuff and end up in the _________.

Answer 29

Phagocytosis

Lysosomes

Question 30

What is a disease that is the most severe form of MPS and leads to corneal clouding. What is the other disease that leads to corneal clouding, very rare?

Answer 30

Hurler syndrome

Sly syndrome

Question 31

This disease is X-linked and has NO corneal clounding.

Answer 31

Hunter syndrome

Question 32

What is a protein with a variable but typically a small amount of carbohydrate (2 to 10 sugar residues).

Answer 32

Glycoproteins

Question 33

Membrane bound glycoproteins participate in cell surface recognition by what 3 ways?

Answer 33

cell to cell contact
hormones
viruses

Question 34

IN the golgi, glycoproteins to be secreted from the cell are packaged into vesicles that fuse with the cell memabrane and release their content

Answer 34

Soluble glycoproteins

Question 35

Glycoproteins destined to be components of the cell membrane are integrated into the ER membrane, pass through the Golgi, and are packaged into vesicles targeted for delivery to the cell membrane

Answer 35

Membrane glycoproteins

Question 36

This occurs in the ER, additional sugars and modifications may be added in Golgi

Answer 36

N-linkage

Question 37

This occurs only in the Golgi apparatus

Answer 37

O-linkage

Question 38

_________ glycoproteins can be phosphorylated at specific mannose residues

Answer 38

N-linked

Question 39

What disease is a deficiency in the ability to phosphorylate mannose…
Accumulation of large lysosomal inclusion bodies

Answer 39

I-cell disease