Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cell & Molec FINAL > Cell Junctions and the Extracellular Matrix > Flashcards

Cell Junctions and the Extracellular Matrix Flashcards

1
Q

What do cellular junctions link together?

A
  • Cells together
  • Attaches cells to extracellular material
    ~ does so through cytoskeleton
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do tight junctions do?

A

= occluding junction
- Form a network around the apical surface
- Composed of two membrane proteins= Claudin and Occludin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do Claudin and Occludin do?

A

Link to actin cytoskeleton via adaptor protein (ZO-1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

For tight junctions, can tracers injected into gut or between basolateral surfaces of cells pass?

A

NO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do tight junctions maintain polarity of epithelia?

A
  • Physically separate apical and basolateral surfaces
  • Contents of the intestine must pass through cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Adherens junctions

A

= anchor adjacent cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cadherins

A

Transmembrane proteins that span the gap between cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What link cadherins to actin filaments inside the cell?

A

alpha and beta catenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

During Adherens Junctions, what is it called when a ring forms around epithelial cell in a layer?

A

Adhesion belt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Desmosomes

A

= anchor adjacent cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cadherins

A

span inter membrane space
- attach to an intracellular “plaque” attached to intermediate filaments (keratin to skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What kinds of tissues are desmosomes most prevalent in?

A

Tissues subject to mechanical stress
(ex. skin, gut, epithelium, muscle, etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Hemidesmosomes

A

= attach cells to basal lamina
- resemble half of a desmosome
- composed of integrins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do integrins do?

A

Link intermediate filaments (keratin) to basal lamina (collagen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Gap junctions

A

= create aqueous pores between cells
- allows chemical communications between cells in a tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Connexins

A

span membrane/interact with those of adjacent cells (connexon hexamer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do connexins do?

A

causes gap junctions to open or close
- ex. closes in response to increase in Ca2+ (calcium) released by ER; happens when cell is damaged

18
Q

Tight junctions!

A

Function: seal spaces between cells
Transmembrane proteins: Caudin & Occludin
Cytoskeleton attachment: Actin (through ZO-1)

19
Q

Adherens junctions!

A

Function: Cell-cell anchoring
Transmembrane proteins: Cadherins
Cytoskeleton attachment: Actin (through alpha and beta catenin)

20
Q

Desmosomes!

A

Function: Cell-cell anchoring
Transmembrane proteins: Cadherins
Cytoskeleton attachment: Intermediate filaments

21
Q

Hemidesmosomes!

A

Function: anchor cell to basal lamina
Transmembrane proteins: Integrins
Cytoskeleton attachment: Intermediate filaments

22
Q

Gap junctions!

A

Function: cell-cell communication
Transmembrane proteins: Connexin (Hexamer=Connexon)
Cytoskeleton attachment: none

23
Q

Tissues

A

collection of similar cells that perform a limited number of specialized functions

24
Q

What are the four basic types of tissues?

A

1.) Muscle
2.) Nervous
3.) Epithelial
4.) Connective

25
Q

What are the two surfaces of epithelial tissue?

A

1.) Apical surface
2.) Base/Basal lamina

26
Q

Apical surface

A

faces exterior body or internal space

27
Q

Base/Basal lamina

A

attached to adjacent tissues
- Mostly collagen and laminin
- Separates epithelia from connective tissue

28
Q

Connective tissue

A

involved in cell movement, differentiation, and communication
- produces the extracellular matrix (ECM)

29
Q

3 basic components of connective tissue

A

1.) Extracellular protein fibers
2.) Ground substance (fluid)
3.) Specialized cells

30
Q

Extracellular protein fibers

A

Give tensile strength
- Ex. collagen, laminin, fibronectin, etc.

31
Q

Ground substance (fluid)

A

resists compression

32
Q

Specialized cells

A
  • Ex. fibroblasts, macrophages, mast cells, etc.
33
Q

ECM forms scaffold for building organs

A

Removal of cells using detergent= “organ ghost” (remaining ECM)
- can repopulate with donor cells= heart starts beating again

34
Q

What is the most abundant protein in animals (30%)

A

Collagen

35
Q

What is synthesized in the RER in fibroblast cells

A

Procollagen

36
Q

Collagen

A

molecules form a triple helix held together by hydrogen bonds

37
Q

What self assembles in extracellular space in a staggered fashion, forming fibrils

A

Collagen
- often arranged at right angles to increase tensile strength

38
Q

Fibrils associate to form what?

A

fibers
- crosslinks give added strength

39
Q

What links cell to ECM (hemidesmosomes)

A

Integrins
- anchored to actin filaments inside the cell

40
Q

Fibronectin

A

Protein in ECM bound to collagen
- Integrins bind to fibronectin
- Most cells prefer to grow when in contact with fibronectin/ECM

41
Q

When do most cells prefer to grow?

A

when in contact with fibronectin/ECM

Cell & Molec FINAL (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions