Lecture 06

Question 1

What type of junction is more prominent in epithelial tissues?

Answer 1

Cell-cell junctions

Question 2

In what type of animal tissues is cell-matrix junctions more prominent?

Answer 2

Connective tissues (i.e. blood, adipose, dense, loose, cartilage)

Question 3

What are the 6 various junctions of cells?

Answer 3

1. Tight junction
2. Adherens junction
3. Desmosome
4. Gap junction
5. Hemidesmosome
6. Actin-linked cell-matrix junction

Question 4

Adherens junction, desmosome, hemidesmosome,
and actin-linked cell-matrix junction are also called the _______________.

Answer 4

Anchoring junctions

Question 5

T or F. The anchoring junctions plus the gap junction make up the junctional complex.

Answer 5

False. The anchoring junctions plus the TIGHT junction make up the junctional complex. The gap junction is excluded from the junctional complex.

Question 6

Seals the gap between cells to prevent molecules from leaking across the epithelium

Answer 6

Tight junction

Question 7

Group the 4 anchoring junctions in terms of (transmembrane) adhesion proteins.

Answer 7

1. Cadherins - adherens junction & desmosome
2. Integrins - actin-linked cell-matrix junction & hemidesmosome

Question 8

Group the 4 anchoring junctions in terms of cytoskeletal component.

Answer 8

1. Actin - adherens junction & actin-linked cell-matrix junction
2. Intermediate filament - desmosome & hemidesmosome

Question 9

Word(s) association. Junction made up of:
Actin; Cadherins

Answer 9

Adherens junction

Question 10

Word(s) association. Junction made up of:
Nonclassical cadherins; Actin

Answer 10

DOES NOT EXIST

Question 11

Word(s) association. Junction made up of:
Intermediate filament; Integrins

Answer 11

Hemidesmosome

Question 12

Word(s) association. Junction made up of:
Cadherins; Intermediate filament

Answer 12

Desmosome

Question 13

Word(s) association. Junction made up of:
Actin; Integrins

Answer 13

Actin-linked cell-matrix junction

Question 14

T or F. The cadherins of bacteria are always connected to actin filaments.

Answer 14

False. Bacteria has NO cadherins

Question 15

Where do cadherins take their name from?

Answer 15

Their dependence to Ca2+

Question 16

Which type of cells do NOT have cadherins?
a. epithelial
b. nerve
c. placenta
d. lens
e. none of the above

Answer 16

E. All these cells have cadherins.

Question 17

T or F. Integrins mediate homophilic adhesion.

Answer 17

False.
Cadherins - homophilic.
Integrins - heterophilic.

Question 18

Mechanotransduction is present in which junction?

Answer 18

Adherens junction

Question 19

Helps prevent apical or basolateral transport proteins from diffusing into the other region.

Answer 19

Tight junctions

Question 20

Movement of ions and other molecules between epithelial cells

Answer 20

Paracellular transport

Question 21

Two main tight junction proteins

Answer 21

Claudin and occludin

Question 22

Claudin functions for _____________ while occludin governs ______________.

Answer 22

assembly of the sealing strands; junction permeability

Mnemonic: CLaudin CLoses. Occludin Opens

Question 23

Large scaffold proteins providing structural support on which tight junction is built.

Answer 23

ZO (zonula occludens)