Lecture 7

Question 1

Collagen family consists of _____ chains arranged in a _____

Answer 1

3 different chains in triple helix

Question 2

Key cellular protein invoved in Cell - ECM adhesion

Answer 2

Integrins

Question 3

Inegrins

Answer 3

Play a role in cell adhesion and transmembrane signal transduction

Question 4

Collagen fibrils form

Answer 4

Form a basic insolble framework of the ECM

Question 5

Laminins form

Answer 5

Parallel network to collagen

Question 6

Proteoglycans

Answer 6

Fillers of the ECM

Question 7

Fibronectin and Laminin

Answer 7

Strengthen the ECM

Question 8

Structure of Integrins

Answer 8

• Glycoproteins
• 2 Membrane spanning polypeptide chains
• Transmembrane Protein

Question 9

Active form of integrin

Answer 9

Upright

Question 10

Inactive form of integrin

Answer 10

Bent

Question 11

Which membrane protein is a heterodimer

Answer 11

Integrin

Question 12

Main Functions of Inegrins

Answer 12

1. Cell Adhesion
2. Signal Transduction

Question 13

Two Types of Integrin Signalling

Answer 13

1. Outside in
2. Inside Out

Question 14

Example of Outside in Signalling

Answer 14

• Cytoplasmiv tyrosine kinases
• FAK
• Src
• Activation - Phophyrlation of proteins

Question 15

Outside in signals influence cell

Answer 15

• Differentiation
• Motility
• Growth, survival

Question 16

Normal cells

Answer 16

• Survive cultured on solid substratum (Integrin binding)
• Die in suspension

Question 17

Malignant cells

Answer 17

Can grow in suspension - Integrin independent

Question 18

Which amino acid influences Integrin Binding Sequence

Answer 18

• RGD
• Argenine , Glycine , Aspartic Acid

Question 19

Where does RGD Bind to

Answer 19

Fibronectin
Laminin
Proteoglycans

Question 20

Cell to Cell Junctions

Answer 20

• Protein structures that physically connect cells
• Only found in immobile cells

Question 21

Any tissue that faces the external enviroment

Answer 21

Epithelial Tissue

Question 22

Types of Epithelial Sheets

Answer 22

• Columnar
• Squamous
• Cuboidal
• Stratified (Multiple layers)

Question 23

Apical side

Answer 23

Free Surface

Question 24

Basal side

Answer 24

• Basal Lamina
• Connective tissue

Question 25

Hemidesmosomes are composed of ______

Answer 25

Integrin molecules

Question 26

Inracellular linker proteins of Hemidesmosomes

Answer 26

Keratin

Question 27

Extracellular linkage with the basement membrane binds with

Answer 27

Laminin

Question 28

Tight Junctions

Answer 28

- Apical side - Seal adjacent cell plasma membranes - Prevent passage of H2O, small proteins, bacteria

Question 29

Major Proteins that make up tight junctions

Answer 29

- Claudins - Occludins

Question 30

Cadherins

Answer 30

- Glycoprotein - Embryonoc development - Important in malignancy

Question 31

What kind of junctions do cadherins make

Answer 31

- Adherins - Desomsomes

Question 32

What do adherins do

Answer 32

- Structural support - Tensile strength - Anchor themselves by actin molecules

Question 33

3 major components of Adherens junctions

Answer 33

- Actin filaments: Provide cellular shape - Protein Plaques: Anchor membrane, bind to actin - Cadherins: Attach to protein plaques, connect to cadherins on their cells

Question 34

Role of desmosomes

Answer 34

- Bind to intermediate filaments (keratin) - Desmoglein

Question 35

Pemphigus vulgaris is caused by

Answer 35

Desmoglein

Question 36

Gap junctions are used for

Answer 36

- Intracellular junctions - Connect adjacent cells

Question 37

What are gap junctions formed by

Answer 37

Connexin