Exam 2: Collagen + Gylcoproteins

Question 1

Which collagen can be found in bundles of fibers?

Answer 1

Type 1

Question 2

Which collagen is found in most basement membranes?

Answer 2

Type IV

Question 3

Which collagen is found in small amounts and pulls together the other collagens?

Answer 3

Type V

Question 4

Where can tubule composition be found?

Answer 4

Within dentin

Question 5

What fills the spaces between tubules?

Answer 5

Intertubular dentin + collagen

Question 6

Where is collagen not abundantly found?

Answer 6

Enamel of the teeth
*this is why enamel is harder than dentin

Question 7

33% of type I collagen is made up of which amino acid?

Answer 7

Glycine

Question 8

15% of type I collagen is made up of which amino acid?

Answer 8

Proline
*will not form alpha helix or beta sheets because of this

Question 9

How many amino acids per turn in collagen?

Answer 9

3 (Gly, X, Y)

Question 10

Initially, is a collagen helix a left or right-handed turn?

Answer 10

Left-hand turn

Question 11

Every third amino acid is ___?

Answer 11

Glycine

Question 12

When the collagen helices come together are they left or right-handed?

Answer 12

Right-handed: they are made up of left-handed interiors and right-handed exteriors

Question 13

What is the collagen helix commonly referred to?

Answer 13

Coiled-coil structure

Question 14

Hydroxylation of proline helps with what?

Answer 14

Thermal stability of the helix

Question 15

Where can type I collagen be found?

Answer 15

Oral cavity, bone, tendons, ligament, skin

Question 16

Where can type III collagen be found?

Answer 16

Skin, blood vessels, internal organs

Question 17

Where can type IV collagen be found?

Answer 17

Basal lamina

Question 18

What is co-translational synthesis?

Answer 18

Making hydroxy-proline and hydroxy-lysine at the same time as collagen is being synthesized

Question 19

What does hydroxylation of Pro and Lys require?

Answer 19

O2, Fe+2, alpha-ketoglutarate, and vitamin C

Question 20

What is a vitamin C deficiency called?

Answer 20

Scurvy

Question 21

Why does scurvy not impact bone as much as it does teeth, gums, and collagen stability?

Answer 21

Because collagen does not turn over as often in bone, so it’s less affected

Question 22

Glycosylation is the process of ___?

Answer 22

Adding sugars

Question 23

What are propieces?

Answer 23

They are pieces present during initial collagen synthesis but will eventually be removed

Question 24

Where can pro-pieces be found?

Answer 24

N and C-termini’s

Question 25

Do C or N terminal propieces facilitate triple helix formation?

Answer 25

C-terminal

Question 26

What do propieces help prevent?

Answer 26

Premature aggregation: they prevent early collagens from interacting with one another

Question 27

How does staggered arrangement help collagen strength?

Answer 27

With no flushed joints, they are more structurally integral (can't be easily ripped apart)

Question 28

Which collagen type is more like a "rug" or sheet and which are like fibers?

Answer 28

Rug: type IV Fiber: type I and III

Question 29

Does crosslinked collagen increase or decrease with age?

Answer 29

Increase

Question 30

What is the purpose of crosslinking collagen triple helices?

Answer 30

Increases thermal stability

Question 31

Lysine amino oxidase is a ___ requiring enzyme:

Answer 31

Copper

Question 32

What is osteogenesis imperfecta?

Answer 32

Loss of type I collagen

Question 33

What is dentineogenesis imperfecta?

Answer 33

Occurs without bone involvement (so not type I collagen), and instead involves the loss of dentin formation

Question 34

What is amelogenesis imperfecta?

Answer 34

Affects enamel formation

Question 35

What is Ehlers-Danlos IV?

Answer 35

Defects in collagen type III genes

Question 36

What is Ehlers-Danlos VI?

Answer 36

Defects in collagen type I and type III genes

Question 37

Symptoms of Ehlers-Danlos's disorder include:

Answer 37

Hyper-extensive skin, joint hypermobility, translucent skin

Question 38

Symptoms of osteogenesis imperfecta include:

Answer 38

Soft, fragile bones, teeth with short constricted roots, detin hypertrophy/dysplasia

Question 39

Symptoms of dentinogenesis imperfecta include:

Answer 39

Dental effects but no bone involvement; weak + discolored teeth

Question 40

Symptoms of amelogenesis imperfecta include:

Answer 40

Enamel hypoplasia (enamel doesn't develop properly)

Question 41

What is special about elastin's structure?

Answer 41

They can be stretched but will return back to their structure when tension is released

Question 42

What is the definition of carbohydrates?

Answer 42

Polyhydroxy aldehydes or ketones

Question 43

What are some synonyms for carbohydrates?

Answer 43

Saccharides and sugars

Question 44

What is the function of carbohydrates?

Answer 44

Metabolic fuels, energy storage, structural framework of cells, components of nucleic acid

Question 45

Can carbohydrates be used to modify proteins?

Answer 45

Yes

Question 46

A-symmetric carbons have?

Answer 46

Different stereoisomers

Question 47

OH on the right

Answer 47

D sugar structure

Question 48

In a ring, if OH is down, up, down, up, etc... then it is:

Answer 48

Glucose

Answer 49

Mannose

Question 50

In a ring, if OH is down, up, down, down, etc... then it is:

Answer 50

Galactose

Question 51

What is the abbreviation for sialic acid?

Answer 51

NANA

Question 52

What is sialic acid/NANA?

Answer 52

It is a sugar; complex carbohydrate

Question 53

What happens when you form a glycosidic bond?

Answer 53

Structure is locked in ring form; becomes a non-reducing sugar

Question 54

Glycosidic linkages can either be:

Answer 54

O-glycosidic or N-glycosidic

Question 55

The complex class is defined by the presence of:

Answer 55

1 carbohydrate (NANA) aka sialic acid

Question 56

Once you reach the high mannose class...

Answer 56

You stop taking away mannose (trimming) and start adding sugars

Question 57

Core oligosaccharides are added ___?

Answer 57

Cotranslationally

Question 58

How are core oligosaccharides anchored to the ER membrane?

Answer 58

Via a linkage with dolichol

Question 59

Where does processing occur as proteins transit the secretory pathway?

Answer 59

In multiple compartments

Question 60

Glycosylation occurs through an ordered series of processing reactions that involves ___?

Answer 60

Trimming and adding carbohydrates

Question 61

What happens if you replace Glycine in a colllagen coil with a bulkier amino acid?

Answer 61

There will be defects