Epithelial arch.

Question 1

Cell-cell junctions regulate gene expression which is important in what 2 processes?

Answer 1

Cancer development, tumor metastases

Question 2

The ___________ plays a role in initiating cell-cell communication

Answer 2

Desmosome

Question 3

____________ is usually degraded by ubiquitin and is normally linked to e-cadherin

Answer 3

Beta-catenin

Question 4

The ________-bound form of tubulin polymerizes which the ________-bound form depolymerizes

Answer 4

GTP, GDP

Question 5

Cell-cell contact is mediated by what anchor protein?

Answer 5

Desmosomes

Question 6

Cell-matrix interactions are mediated by what proteins?

Answer 6

Hemidesmosomes

Question 7

What filament is the most stable? Why is that?

Answer 7

Intermediate filaments, they are not polarized

Question 8

What filament provides mechanical strength?

Answer 8

Intermediate filament

Question 9

Desmosomes function to attach cell surface adhesion molecules but what other function do they serve?

Answer 9

Cell-cell contact signals

Question 10

_____________ helps organize cell content and organelles

Answer 10

Actin (microfilaments)

Question 11

Phalloidin acts on what filament?

Answer 11

Actin

Question 12

Growing microtubules have ____ bound while shrinking have _____ bound. Actin polymerizes with _______ bound to it and destabilizes with _________ bound.

Answer 12

GTP, GDP, ATP, ADP

Question 13

Actin polymerization controls what 3 cell movement structures? What do they do?

Answer 13

Filopodia-microspikes
Lamellipodia - two dimensional sheets
Pseudopodia - 3D projections in neutrophils

Question 14

Actin filament grow by the process of ____________ which involves ________ _________ proteins.

Answer 14

Nucleation, actin-related

Question 15

Listeria monocytogenes seeks to mimic what?

Answer 15

ARP

Question 16

What are the four types of cell-cell junctions?

Answer 16

Anchoring - hold cells in place
Occluding - separates basal and apical
Channel-forming - allows cell communication
Signal-relaying - NMJ

Question 17

Weak adhesion forces are due to ___________ receptors, while stronger forces are due to __________

Answer 17

Heterophilic, homophilic

Question 18

__________ ____________ seals gap between epithelial cells

Answer 18

Tight junction

Question 19

___________ _________ connects actin filaments in one cell to the actin in the next

Answer 19

Adherens junction

Question 20

_______________ connects intermediate filaments in one cell to those in the next cell

Answer 20

Desmosome

Question 21

_________ _____________ allow the passage of small water soluble molecules and ions from cell to cell

Answer 21

Gap junction

Question 22

_________________ anchors intermediate filaments in a cell to extracellular matrix

Answer 22

Hemidesmosome

Question 23

What 4 things does a tight junction do?

Answer 23

Recruit cytoskeleton
Recruit signaling molecules
Form a fence
Vectorial transfer

Question 24

Gap junctions allow molecules smaller than __________ da to pass through.

Answer 24

1000

Question 25

What two proteins are related to gap junctions?

Answer 25

Connexin and innexin

Question 26

Connexin is composed of ____ subunits

Answer 26

6

Question 27

What causes gap junctions to immediately close as to not affect nearby cells

Answer 27

Ca

Question 28

What stops leukocytes at the site of inflammation?

Answer 28

Integrins

Question 29

Intergin affects proliferation, differentiation, protein synth., attachment, migration, and shape change through what process?

Answer 29

Integrins form focal adhesion complexes which tell the nucleus what changes need to be made

Question 30

What does vinculin bind to?

Answer 30

Actin

Question 31

What is most important in adherens junctions?

Answer 31

Beta-catenin

Question 32

What is important in focal adhesions?

Answer 32

FAK and integrins

Question 33

Actin-linked cell-matrix adhesions act on integrin and extracellular matrix proteins and depend primarily on what proteins?

Answer 33

Focal adhesion kinase (FAK)

Question 34

Why is beta-catenin normally ubiquitinated and destroyed?

Answer 34

This allows fine control of b-catenin. This means that b-catenin is around and ready when it is needed

Question 35

What two ways are cadherin proteins sorted?

Answer 35

They are sorted by different classes of cadherin or a high/low level of one type of cadherin

Question 36

What are the two types of cadherin mediated connections?

Answer 36

``` Non-classical = desmosomes Classical = Ca dependent adherens ```

Question 37

Classical caherins are involved in ______________ ____________ and ________________

Answer 37

Adherens junctions, synapses

Question 38

Desmosomal cadherin are involved in ______________

Answer 38

Desmosomes

Question 39

Cadherin proteins cluster at sites of ______________________

Answer 39

Cell-cell contact

Question 40

ARVC (arrhythmogenic right ventricular cardiomyopathy) is caused by __________________________________

Answer 40

Missense mutations in desmocollin-2

Question 41

Pemphigus foliaceus is an ____________________ disorder which causes _____________ in which the antibodies target ______________

Answer 41

Autoimmune, blistering, desmoglein 1

Question 42

What type of cell secretes most of the ECM?

Answer 42

Fibroblast

Question 43

The basal lamina in the kidney glomerulus functions as a _______________

Answer 43

filter

Question 44

The ___________________ and the ________________ combined make up the basement membrane

Answer 44

Reticular lamina, basal lamina

Question 45

The __________ lamina is more superficial than the _________ lamina

Answer 45

Basal, reticular

Question 46

What residues are hydroxylated in the ER lumen? Which is then glycosylated?

Answer 46

Proline and lysine, lysine

Question 47

Scurvy can be caused by a loss of what?

Answer 47

Ascorbate or iron

Question 48

What are some symptoms of scurvy?

Answer 48

Poor wound healing, loss of teeth, pale skin, and sunken eyes

Question 49

Marfan's syndrome is due to defects in _____________. These patients have an increased risk of ______________ _______________.

Answer 49

Elastin, aortic aneurysm

Question 50

Ehlers-Danlos syndrome is caused by a defect in what molecule?

Answer 50

Collagen

Question 51

Elastin is cross linked by _____________ _______________. When this pathway doesn't work in what disease?

Answer 51

Lysyl oxidase, marfans

Question 52

Where are stem cells stored?

Answer 52

They are stored in bulges that are halfway to the cell surface

Question 53

What is terminal differentiation?

Answer 53

The tendency of cells to move toward the surface as they become more differentiated

Question 54

Where do olfactory neurons meet before linking to projection neuron?

Answer 54

Olfactory bulb

Question 55

What mode of signaling does olfaction follow?

Answer 55

G-proteins

Question 56

What is the lifespan of olfactory neurons? What regenerates them?

Answer 56

1 month, neural stem cells

Question 57

Basal stem cells, who are in contact with the basal lamina, will begin to differentiate after what event?

Answer 57

Once they lose contact with the basal lamina

Question 58

__________ _______ ____________ help establish atonal guidance pathways to ensure connection to the correct glomerulus

Answer 58

Odorant receptor proteins

Question 59

What is one of the few instances of adult neurogenesis in the CNS

Answer 59

Olfactory receptor cell regeneration

Question 60

Neurodegenerative disorders, such as Parkinson's and Alzheimer's, are often preempted by ____________

Answer 60

Reduced sense of smell

Question 61

What does the rho family of proteins do?

Answer 61

Set up cell polarity, organize cell migration

Question 62

What 3 main proteins are in the rho family? Which is the active state?

Answer 62

Cdc42, Rac, Rho | GTP bound is active

Question 63

Rho activation leads to ___________ ______________ ___________

Answer 63

Stress fiber formation

Question 64

Rac activation leads to _______________ _______________

Answer 64

Lamellipodia extensions

Question 65

Cdc42 activation leads to the formation of ___________. What is their key characteristic?

Answer 65

Filopodia, spiky projections

Question 66

Listeria monocytes and _______ both activate __________. What does it form?

Answer 66

Rac, ARP2/3 complex, lamellipodia

Question 67

Rac activation and rho activation are mutually __________

Answer 67

Anatagonistic | RAC causes extension and Rho causes contraction

Question 68

What serves as a scaffold for actin nucleation

Answer 68

ARP2 and ARP3