Cell Junctions

Question 1

Define: cadherins

Answer 1

Calcium dependent adhesion

Question 2

What are the 4 different kinds of cell junction proteins?

Answer 2

1. Cadherins
2. Integrins
3. Ig-superfamily
4. Selections

Question 3

Are all the links between cells permanent?

Answer 3

No

Question 4

Which are the 4 cell-to-cell junction types?

Answer 4

1. Tight junction
2. Belt desmosome
3. Spot desmosome
4. Gap junction

Question 5

Which desmosome is connects the cell to the ECM?

Answer 5

Hemidesmosome

Question 6

What is the main goal of a desmosome?

Answer 6

To give a cell strength

Question 7

The three types of desmosomes are:

Answer 7

Spot, belt and hemi

Question 8

What are the proteins of a spot desmosome?

Answer 8

Cadherins: desmoglein and desmocolin
Plakin proteins: plakoglobin and desmoplakin
Tonifilaments: keratin

Question 9

What do the keratin filaments of the spot desmosome do?

Answer 9

Connect spot desmosome to spot desmosome

Question 10

What is the cell junction?

Answer 10

An intercellular bridge with integral proteins that often link to cytoskeletal proteins

Question 11

Which cadherins in the spot desmosome junction keep the desmosome together?

Answer 11

Desmocolin and desmoglein

Question 12

What do hemidesmosomes do?

Answer 12

They link the cell to the ECM

Question 13

What is the purpose of the plakin proteins?

Answer 13

help distribute stress

Question 14

Which proteins allow the integral proteins to stay in place?

Answer 14

Desmoglobin and plakoglobin

Question 15

The hemidesmosomes link ____ to _____

Answer 15

cell to ECM

Question 16

Hemidesmosomes are closely related to _____

Answer 16

integrins

Question 17

Hemidesmosomes use ____ and _____

Answer 17

integrins and plakin protein

Question 18

The hemidesmosome link fibers through the ________ then the ______ and then ______ to the ______

Answer 18

plasma membrane then integrin then plakin protein and to the tonofilaments

Question 19

Define: disintegrins

Answer 19

enzymes that breakdown integrins found in venom

Question 20

Which desmosome is linked to actin?

Answer 20

belt desmosome

Question 21

Belt desmosome give the cell the ability to ____ and gives _______

Answer 21

move; lateral stability

Question 22

Belt desmosomes link the ___________

Answer 22

periphery of one cell to the periphery of another

Question 23

A connexon is…

Answer 23

6 connexins

Question 24

A gap junction causes a

Answer 24

1.5 nm channel where water and protons and calcium can move through

Question 25

Gap junctions can…

Answer 25

open and close by twisting

Question 26

DEFINE: OCCLUDING JUNCTION

Answer 26

it prevents movements through the ECM allowing the cells to have a top and bottom

Question 27

The tight junction ____ the ECM

Answer 27

closes

Question 28

Define: tight junction

Answer 28

the tight junction allows the things in tissue to stay in

Question 29

Can large molecules move through plant cells?

Answer 29

Yes