Lecture 22

Question 1

What gives our cells polarity?

Answer 1

an apical and basal surface

Question 2

What is attached to the basal layer?

Answer 2

extracellular matrix (ECM)

Question 3

what two components is the ECM divided into

Answer 3

basal lamina and connective tissue

Question 4

What attaches cells to other cells?

Answer 4

cell-adhesion molecules

Question 5

How are cells anchored to the ECM?

Answer 5

adhesion receptors

Question 6

what are the 5 different types of junctions?

Answer 6

tight, adherens, desmosome, hemidesmosome, gap

Question 7

What are homophilic interactions between cell-adhesion molecules?

Answer 7

proteins on cell 1 are interacting with the same proteins on cell 2

Question 8

What is an example of cell-adhesion molecules that interact homophilically?

Answer 8

cadherins

Question 9

What are heterophilic interactions between cell-adhesion molecules?

Answer 9

example would be how integrins are used in attaching a cell to the ECM via fibronectin – different proteins are used unlike homophilic interactions

Question 10

how do homophilic interactions make a strong more reinforcing interaction/structure?

Answer 10

cadherins on each cell associate with each other cis-laterally and then those cadherins attach to those on another cell (a 2-step process)

Question 11

What are some roles of ECM?

Answer 11

inhibit/facilitate cell movement and reservoir for growth factors

Question 12

What junctions are present in the apical-lateral surface of epithelial cells?

Answer 12

tight junctions

Question 13

What junctions are present in the lateral surface of epithelial cells?

Answer 13

adherens, desmosomes, gap

Question 14

Which cytoskeletal element(s) interact with adherens?

Answer 14

actin/myosin

Question 15

Which cytoskeletal element(s) interact with desmosomes?

Answer 15

intermediate filaments

Question 16

Which cytoskeletal element(s) interact with hemidesmosomes?

Answer 16

intermediate filaments

Question 17

Which cytoskeletal element(s) interact with tight junctions?

Answer 17

actin filaments

Question 18

What junctions are present in the lateral-basal surface of epithelial cells?

Answer 18

hemidesmosome

Question 19

What do cadherins need to be bound to in order to function?

Answer 19

calcium

Question 20

Function of cadherins?

Answer 20

gives cells shape and tension, it can participate in cell signaling

Question 21

What are desmosomes?

Answer 21

they are a type of cadherins

Question 22

What do desmosomes attach to?

Answer 22

cytoplasmic plaque via adapter proteins

Question 23

Functions of desmosomes?

Answer 23

strength, durability, and signaling

Question 24

What do hemidesmosomes attach to?

Answer 24

integrin and ECM

Question 25

Functions of hemidesmosomes?

Answer 25

shape, rigidity, and signaling

Question 26

Functions of tight junctions?

Answer 26

important in sealing off body cavities and controlling solute flow, signaling

Question 27

What are tight junctions made of

Answer 27

3 types of transmembrane proteins (1 membrane domain or 4 membrane domains)

Question 28

What does paracellular pathway refer to?

Answer 28

refers to moving molecules in between cells

Question 29

What does transcellular pathway refer to?

Answer 29

refers to how the cell's receptor will pick up the molecule and bring it to the other end

Question 30

function of gap junctions

Answer 30

small molecule transport, communication

Question 31

function of adherens

Answer 31

shape, tension, signaling

Question 32

Parts of basal lamina/ECM

Answer 32

fibronectin, laminin, collagen

Question 33

What is an example of hemidesmosomes?

Answer 33

integrin

Question 34

type IV collagen

Answer 34

sheet-forming collagen, major structural component of the basal lamina

Question 35

type II collagen

Answer 35

cartilage

Question 36

type I collagen

Answer 36

tendons

Question 37

proteoglycans

Answer 37

proteins that associate with a bunch of carbohydrates, cushions in connective tissues

Question 38

hyaluronan

Answer 38

resists compression, facilitates cell migration, and gives cartilage its gel-like properties

Question 39

fibronectin

Answer 39

binds with integrin connecting cells and ECM, influencing cell shape, differentiation, and movement

Question 40

function of fibronectin

Answer 40

functions in cell shape and movement

Question 41

extravasation

Answer 41

cells leave the blood stream and get into tissue