NPLEX

Question 1

Type 1 collagen:
category, location, disorder

Answer 1

fibrillar
bone, tendon, dentin
skin, fascia, cornea
late wound repair
oteogenesis imperfecta

Question 2

type 2 collagen
category, location, disorder

Answer 2

fibrillar
cartilage,nucleus pulposus
vitreous body
achondrogenesis

Question 3

type 3 collagen
category, location, disorder

Answer 3

fibrillar
reticulin: skin, vasculature, uterus
early wound repair
fetal tissue
EDS (vasculare)

Question 4

type 5 collagen
category, location, disorder

Answer 4

fibrillar
bone, skin, fetal tissue, placenta
EDS classical

Question 5

type 4 collagen
category, location, disorder

Answer 5

network
basement membrane: lens, cochlea, glomerulus
alport syndrome, goodpasture

Question 6

type 7 collagen
category, location, disorder

Answer 6

anchoring
skin
epidermolysis bullosa

Question 7

Structure of collagen:

Answer 7

3 alpha chain monomers –> triple helix –> cross linked collagen

Question 8

helical structure amino acid repeat pattern?
what is the X and Y?

Answer 8

Gly-X-Y
X is usually proline
Y is usually lysine (hydroxylated)

Question 9

Nomenclature for gene mutations in collagen?

Answer 9

nomenclature: COL _ A _ (# of collagen type, specific identifier)

Question 10

Wound healing - proliferative phase:
days, and what type of collagen

Answer 10

-fibroblasts are stimulated to secrete type 3 collagen fibrillation tissue ( granulation tissue)

Question 11

wound healing maturation phase
-regulated by what protein? what does the protein need?

Answer 11

-type 3 collagen is being remodeled to type 1 collagen and becoming much stronger
(scar formation)
- regulated by matrix metalloproteinase (MMPs) - breaks down collagen, but requires zinc!
- this is why you get delayed wound healing with zinc deficiency

Question 12

Describe steps of hydroxylation:

Answer 12

• ## addition of OH group to lysine and proline residues

Question 13

where does collagen synthesis take place?

Answer 13

• starts wiht collagen mRNA in the nucleus then the SRP takes it to the rough ER
• rough ER !!!!!!!

Question 14

what vitamin does hydroxylation require?

Answer 14

Vitamin C

Question 15

glycosylation:

Answer 15

-addition of sugar group onto alpha chain lysine/proline to form hydroxylysine/ hydroxyproline residues
- makes a tag / marker for hydroxylation
- happens after hydroxylation

Question 16

Osteogenesis imperfexta
- gene mutation?

Answer 16

failure or procollagen / the triple helix to form
-COL1A1 or COL1A2 gene mutation

Question 17

What enzyme that has a defect in EDS?

Answer 17

• Procollagen peptidase

Question 18

what mineral does lysyl oxidase require to do the lysine - hydroxylysine cross linking

Answer 18

copper!

Question 19

what is the NA+ / K+ pump powered by?

Answer 19

ATP

Question 20

Describe Na+/ K+ pump

Answer 20

active
3 Na+ move to the outside (nikki is on the inside and wants out)
2 K+ move to the inside (perry is on the outside and wants in)

Question 21

What does it mean “ATP phosphorylates”?
What does this trigger

Answer 21

ATP loses a phosphate and becomes ADP
- triggers a conformational change

Question 22

Primary ciliary dyskinesia:

Answer 22

defect in dynein leads to absent or dysmotile cilia which leads to dysfunctional epithelia

Question 23

Describe actin

Answer 23

G actin monomers -> F actin polymers creates a double helix
Small!

Question 24

intermediate filaments are cross linked by what?

Answer 24

plectin

Question 25

are microtubules polarized?

Answer 25

yes

Question 26

dynein moves:

Answer 26

retrograde (moves back toward nucleus)

Question 27

kinesin moves:

Answer 27

anterograde (towards periphery)

Question 28

what protein creates lewy bodies? what causes it?

Answer 28

alpha synuclein protein -decreases ubiquitin proteasome activity leads to neurodegeneration because decrease parkin activity (decrease E3 ) leads to increase DUB

Question 29

Gene mutation in osteogenesis imperfecta:

Answer 29

COL1A1/COL1A2 - can't make the procollagen triple helix

Question 30

what is tetrahydrofolate? - what vitamin makes it?

Answer 30

- carrier of one carbon group - purine and pyrimidine synthesis

Question 31

dihydrofolate reductase does:

Answer 31

- reduction reaction (need electrons from NADPH for power) - converts folic acid to DHF then to THF

Question 32

MTHFR is an enzyme that does that:

Answer 32

an enzyme that turns N5N10-methylene-THF into N5-methyl-THF which is the active form!

Question 33

Methotrexate (DMARD):

Answer 33

inhibits DHF reductase and results in folates trapped as dihydrofolate (DHF), don't get to the usable form of tetrahydrofolate (THF)

Question 34

2 amino acids that are major sources of 1 carbon group:

Answer 34

- serine and glycine

Question 35

what enzyme converts methanol to formaldehyde?

Answer 35

alcohol dehydrogenase

Question 36

what enzyme converts formaldehyde to formate?

Answer 36

aldehyde dehydrogenase

Question 37

methylated acceptors:

Answer 37

-synthesis of creatine, choline, epinephrine - DNA methylation (inactivation) - 5' methyl-guanasine caps in mRNA (post-translational -protein methylation - histones

Question 38

what does the activated methyl group cycle create:

Answer 38

SAM (S-adenyosyl-methionine)

Question 39

methionine synthase does: - requires:

Answer 39

converts homocysteine to methionine -B12