Cell Junctions- Mozarn

Question 1

specialized regions where cells are attached to each other and the ECM

Answer 1

cell junctions

Question 2

the type of tissue that is particulary rich in cell junctions

Answer 2

epithelial tissues

Question 3

cell to cell junctions found in all epithelia

Answer 3

tight junctions

Question 4

The junction that severely limits the intercellular permeability and maintain cell membrane polarity

Answer 4

tight junctions

Question 5

formed by sealing strands anchored in the membrane

Answer 5

tight junctions

Question 6

required for active transport of solutes across the epithelial barrier

Answer 6

tight junctions

Question 7

all tight junctions are ______ to macromolecules, but ______ to small molecules varies greatly depending on the number of sealing strands the different transmembrane protein composition

Answer 7

impermeable to macro

permeable to small molecules

Question 8

transmembrane proteins that comprise tight junctions

Answer 8

occludins and claudins

Question 9

binds cells to each other and to the ECM

Answer 9

anchoring junctions

Question 10

Anchoring junctions are found in _____ tissues, especially those who under go a lot of ______ stress.

Answer 10

All tissues; especially those who undergo mechanical stress

Question 11

The four types of anchoring junctions:

Answer 11

adherens junctions, desmosomes, hemidesmosomes, and focal adhesions

Question 12

Just like tight junctions, adherens junctions are alls cell to cell junctions found in primarily_______.

Answer 12

all epithelia

Question 13

These from a continuous adhesion belt just below the tight junction

Answer 13

adherens junctions

Question 14

the transmembrane proteins of adherens junctions

Answer 14

cadherins

Question 15

adheren junctions connect bundles of ____ filaments thus making it _______.

Answer 15

Actin filaments; contractile

Question 16

Adherens junctions are necessary for _______ formation and _______ formation in morphogenesis

Answer 16

tight junction formation and epithelial tube formation

Question 17

cell to cell junctions that “rivet” cells together and found primarily in both epithelial cells and muscle cells

Answer 17

desmosomes

Question 18

These type of junctions contribute to strength and durability

Answer 18

desmosomes

Question 19

the transmembrane proteins of desmosomes

Answer 19

cadherins

Question 20

these resemble half-desmosomes, but _____ cells to the ECM

Answer 20

hemidesmosomes and bind cells to the ECM

Question 21

transmembrane adhesion proteins of hemidesmosomes are____.

Answer 21

integrins (while desmosomes and adherens junctions are cadherins)

Question 22

Spot type junctions that link the cell cytoskeleton to the ECM

Answer 22

Focal adhesions

Question 23

focal adhesions can contain as many as _____ different proteins

Answer 23

100

Question 24

focal adhesions are ________ because they can form, change, or disappear in response to the intracellular or extracellular signals

Answer 24

dynamic

Question 25

Focal adhesions transmit external mechanical signals via ______ receptors

Answer 25

integrin receptors

Question 26

Focal adhesions are important in cell migration, _____ differentiation, proliferation, and _______ tooth movement.

Answer 26

motility and ortho movements

Question 27

communicating junctions found in nearly all cells except skeletal muscle and blood cells

Answer 27

gap junctions

Question 28

These allow for small molecules and electrical charges to pass directly from cell to cell

Answer 28

gap junctions

Question 29

Gap junctions form channels called _____ which are hexamers of _____ protein.

Answer 29

connexons; connexin proteins

Question 30

Connexon permeability varies with ______ and ______.

Answer 30

identity and combinations of connexins present

Question 31

Gap junction permeability can be regulated by …..

Answer 31

both intra- and extra-cellular signals.

Question 32

Allow cells of a given tissue to function together quickly and in coordinated fashion.

Answer 32

gap junctions

Question 33

adherens junctions and desmosomes do:

and what type of transmembrane protein:

Answer 33

connect neighboring cells and made up of cadherin proteins

Question 34

focal adhesions and hemidesmosomes do:

and what type of transmembrane protein:

Answer 34

bind cells to ECM

and transmembrane adhesion proteins belong to the integrin family