Lecture 1 (Colombo)

Question 0

What is the structural function of microfilaments?

Answer 0

Microvilli, filopodia, and they give shape to the cells. They also form tracts for myosin, giving contractility

Question 1

What are microfilaments composed of?

Answer 1

Actin

Question 2

What are intermediate filaments made of?

Answer 2

Different in various tissues. Vimentin for cells of mesenchymal origin, cytokeratin

Question 3

What is the purpose of intermediate filaments?

Answer 3

Anchors, Structural. They are non contractile

Question 4

What are microtubules made of?

Answer 4

Tubulin

Question 5

What is the function of microtubules?

Answer 5

Monorail system (kinesins), Cilia and flagella (dynein)

Question 6

Tight junctions hold cells together by binding to what cytoskeletal structure?

Answer 6

Microfilaments

Question 7

What are the three transmembrane proteins that bind to each other in a tight junction?

Answer 7

Claudins, Occludins, and JAM

Question 8

What two main components make up cell to cell adhesive junctions?

Answer 8

Cadherins (outside) and Cantinins (inside)

Question 9

Cadherins are dependent on what ion?

Answer 9

Ca++

Question 10

What is the function of focal adhesion junctions?

Answer 10

Hold the cell to the ECM

Question 11

What element of the focal adhesion holds the cell to the ECM?

Answer 11

Integrins. They replace the cadherin as the transmembrane component

Question 12

Desmosomes are similar to cell-cell adhesions in what manner?

Answer 12

They both have cadherins and catinins

Question 13

Cell-cell adhesions bind to what cytoskeletal structure?

Answer 13

Microfilaments

Question 14

Desmosomes bind to what cytoskeletal structure?

Answer 14

Intermediate filaments

Question 15

Focal adhesions attach to what cytoskeletal component?

Answer 15

Microfilaments

Question 16

Hemidesmosomes attach to what cytoskeletal component?

Answer 16

Intermediate filaments

Question 17

What are gap junctions?

Answer 17

Cell-Cell aqueous pores

Question 18

What are tonofilaments?

Answer 18

A big bundle of intermediate filaments

Question 19

What is the function of the basal lamina?

Answer 19

It is an anchor for epithelial cells

Question 20

What cell attachment connects to the basal lamina?

Answer 20

hemidesmosomes

Question 21

Name the three components that make up the basal lamina

Answer 21

Lamina lucida, lamina densa, and lamina fibroreticularis

Question 22

What are the components of the lamina lucida?

Answer 22

laminin, entactin, and intergrins

Question 23

What are the components of the lamina densa?

Answer 23

Collagen IV

Question 24

What are the components of the lamina fibroreticularis?

Answer 24

Depends but mostly collagen III

Question 25

True or False: fibroblasts usually have cell-cell connections

Answer 25

False, they rarely do. The one exception is in the periodontal ligament

Question 26

True of False: Fibroblasts age

Answer 26

True, that is why you see slower healing with age

Question 27

Collagen is rich in which two amino acids?

Answer 27

Proline and lysine. (hydrogen bonding allows triple helical assembly)

Question 28

How are collagen fiber assembled?

Answer 28

They are staggered with a 1/4 overlap and aligned in parallel fashion.

Question 29

Why is it important that the collagen fibers are staggered?

Answer 29

If allows them to grow long and strong. It also creates gaps in the fibers and in dentin/bone this is where mineralization occurs

Question 30

What 2 components make up elastic fibers?

Answer 30

Elastin and fibrillin (fibrillin is a glycoprotein that forms a scaffold onto which elastin fibers accumulate)

Question 31

What hormone does elastin secrete?

Answer 31

TGF-beta for healing, but in Marfan's syndrome it just secretes the hormone causing abnormal growth

Question 32

What is the main component of 'ground substance'?

Answer 32

Proteoglycans

Question 33

What make a proteoglycan?

Answer 33

A protein core with glycosaminoglycan chains (GAGs) | Mostly carbohydrate with less protein

Question 34

Proteoglycans are positively or negatively charged?

Answer 34

Negatively, this make them hydrophilic.

Question 35

What is a special function of proteoglycans?

Answer 35

They can make growth factors in the ECM and can help activate GF receptors

Question 36

True or False: glycoproteins have more carbohydrate and less protein

Answer 36

False, that is true of proteoglycans but glycoproteins have more protein and less carbohydrate

Question 37

What is a major player in matrix digestion?

Answer 37

MMPs