Epithelial arch. Flashcards

1
Q

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

A

Cancer development, tumor metastases

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2
Q

The ___________ plays a role in initiating cell-cell communication

A

Desmosome

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3
Q

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

A

Beta-catenin

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4
Q

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

A

GTP, GDP

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5
Q

Cell-cell contact is mediated by what anchor protein?

A

Desmosomes

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6
Q

Cell-matrix interactions are mediated by what proteins?

A

Hemidesmosomes

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7
Q

What filament is the most stable? Why is that?

A

Intermediate filaments, they are not polarized

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8
Q

What filament provides mechanical strength?

A

Intermediate filament

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9
Q

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

A

Cell-cell contact signals

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10
Q

_____________ helps organize cell content and organelles

A

Actin (microfilaments)

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11
Q

Phalloidin acts on what filament?

A

Actin

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12
Q

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

A

GTP, GDP, ATP, ADP

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13
Q

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

A

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

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14
Q

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

A

Nucleation, actin-related

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15
Q

Listeria monocytogenes seeks to mimic what?

A

ARP

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16
Q

What are the four types of cell-cell junctions?

A

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

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17
Q

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

A

Heterophilic, homophilic

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18
Q

__________ ____________ seals gap between epithelial cells

A

Tight junction

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19
Q

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

A

Adherens junction

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20
Q

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

A

Desmosome

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21
Q

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

A

Gap junction

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22
Q

_________________ anchors intermediate filaments in a cell to extracellular matrix

A

Hemidesmosome

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23
Q

What 4 things does a tight junction do?

A

Recruit cytoskeleton
Recruit signaling molecules
Form a fence
Vectorial transfer

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24
Q

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

A

1000

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25
Q

What two proteins are related to gap junctions?

A

Connexin and innexin

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26
Q

Connexin is composed of ____ subunits

A

6

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27
Q

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

A

Ca

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28
Q

What stops leukocytes at the site of inflammation?

A

Integrins

29
Q

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

A

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

30
Q

What does vinculin bind to?

A

Actin

31
Q

What is most important in adherens junctions?

A

Beta-catenin

32
Q

What is important in focal adhesions?

A

FAK and integrins

33
Q

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

A

Focal adhesion kinase (FAK)

34
Q

Why is beta-catenin normally ubiquitinated and destroyed?

A

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

35
Q

What two ways are cadherin proteins sorted?

A

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

36
Q

What are the two types of cadherin mediated connections?

A
Non-classical = desmosomes
Classical = Ca dependent adherens
37
Q

Classical caherins are involved in ______________ ____________ and ________________

A

Adherens junctions, synapses

38
Q

Desmosomal cadherin are involved in ______________

A

Desmosomes

39
Q

Cadherin proteins cluster at sites of ______________________

A

Cell-cell contact

40
Q

ARVC (arrhythmogenic right ventricular cardiomyopathy) is caused by __________________________________

A

Missense mutations in desmocollin-2

41
Q

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

A

Autoimmune, blistering, desmoglein 1

42
Q

What type of cell secretes most of the ECM?

A

Fibroblast

43
Q

The basal lamina in the kidney glomerulus functions as a _______________

A

filter

44
Q

The ___________________ and the ________________ combined make up the basement membrane

A

Reticular lamina, basal lamina

45
Q

The __________ lamina is more superficial than the _________ lamina

A

Basal, reticular

46
Q

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

A

Proline and lysine, lysine

47
Q

Scurvy can be caused by a loss of what?

A

Ascorbate or iron

48
Q

What are some symptoms of scurvy?

A

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

49
Q

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

A

Elastin, aortic aneurysm

50
Q

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

A

Collagen

51
Q

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

A

Lysyl oxidase, marfans

52
Q

Where are stem cells stored?

A

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

53
Q

What is terminal differentiation?

A

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

54
Q

Where do olfactory neurons meet before linking to projection neuron?

A

Olfactory bulb

55
Q

What mode of signaling does olfaction follow?

A

G-proteins

56
Q

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

A

1 month, neural stem cells

57
Q

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

A

Once they lose contact with the basal lamina

58
Q

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

A

Odorant receptor proteins

59
Q

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

A

Olfactory receptor cell regeneration

60
Q

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

A

Reduced sense of smell

61
Q

What does the rho family of proteins do?

A

Set up cell polarity, organize cell migration

62
Q

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

A

Cdc42, Rac, Rho

GTP bound is active

63
Q

Rho activation leads to ___________ ______________ ___________

A

Stress fiber formation

64
Q

Rac activation leads to _______________ _______________

A

Lamellipodia extensions

65
Q

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

A

Filopodia, spiky projections

66
Q

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

A

Rac, ARP2/3 complex, lamellipodia

67
Q

Rac activation and rho activation are mutually __________

A

Anatagonistic

RAC causes extension and Rho causes contraction

68
Q

What serves as a scaffold for actin nucleation

A

ARP2 and ARP3