Mokrzan

Question 1

4 families of ECM

Answer 1

1. Collagen
2. Elastin
3. Glycoproteins
4. Proteoglycans

Question 2

2 types of glycoproteins

Answer 2

1. Fibronectin

2. Laminin

Question 3

Collagen is ___% of total body ____?

Answer 3

30%

Protein

Question 4

Structure of collagen = _______

Stabilized by ________

Answer 4

Triple-helical

Crosslinks

Question 5

Synthesis of collagen is affected by ____

Answer 5

Physiologic conditions (ex. diet or mechanical stress) [Frequently remodeled]

Question 6

A genetic mutation that causes the _____ in ___ collagen to be replaced by another AA is called _____ ____

Answer 6

Glycine
Type I
Osteogenesis/dentogenesis imperfecta

Question 7

Predominant ECM molecule in blood vessels

Answer 7

Elastin

Question 8

ECM component found in skin, lungs, intestines

Answer 8

Elastin (found in organs that require elasticity)

Question 9

Elastin is stabilized by ____

Answer 9

2-way crosslinks

Question 10

How long is elastin synthesized for

Answer 10

Stops after adolescence

Question 11

Function of fibronectin

Answer 11

Facilitates communication btwn IC and ECM
Cell adhesion
Cell growth
Migration
Wound healing

Question 12

Fibronectin binds to _____

Answer 12

Other ECM molecules & integrin molecules on cells

Question 13

Types of fibronectin

Answer 13

At least 20 known types including soluble and insoluble forms

Question 14

Fibronectin produced by

Answer 14

Alternative splicing of a single precursor mRNA

Question 15

Where is laminin primarily found?

Answer 15

Basal lamina

Question 16

Function of laminin

Answer 16

Gives structural support to ECM

Question 17

Major component of basement membranes in epithelial and muscle tissues

Answer 17

Laminin

Question 18

Laminin binds to cells via _____

Answer 18

integrin family of proteins

Question 19

Diseases of defective laminin

Answer 19

Muscular dystrophy
Defects of kidney filter
Epidermolysis bullosa - lethal skin blistering disease

Question 20

Proteoglycans are the __-___ of the ECM

Answer 20

gel-formers

Question 21

Proteoglycans have many ____ charges which attracts ____ & ____. Result is ____ of ECM that provides ____ & _____

Answer 21

Negative
Cations
Water
Hydration
Rigidity
Durability

Question 22

Proteoglycans make up ___% of ECM proteins, but because of _______, ___ ____ fill most of ECM

Answer 22

<10%
hydrophilicity
GAG chains

Question 23

Proteoglycans can combine to form _____

Answer 23

aggrecans

Question 24

Other functions of proteoglycans

Answer 24

Can bind growth factors
Regulate enzyme activity
Act as co-receptors

Question 25

Types of diseases caused by proteoglycan defects

Answer 25

Lysosomal storage diseases

Question 26

3 types of cell junctions

Answer 26

1. Tight junctions 2. Anchoring junctions 3. Gap junctions

Question 27

Types of anchoring junctions

Answer 27

Adherens junctions Desmosomes Hemidesmosomes Focal adhesions

Question 28

This type of tissue is particularly rich in cellular junctions

Answer 28

Epithelial tissues

Question 29

Type of cell-cell junction found in all epithelia

Answer 29

Tight junctions

Question 30

Tight junctions _______ intercellular permeability and ______ cell membrane polarity

Answer 30

Severely limit | Maintain

Question 31

Tight junctions are formed by

Answer 31

Sealing strands anchored in the membrane

Question 32

Tight junctions permeability to macromolecules and small molecules

Answer 32

Active transport required for solutes to cross epithelial barrier Junctions are impermeable to macromolecules Permeability to small molecules varies greatly depending on the # of sealing strands and transmembrane proteins (occludin and claudin families) that comprise them

Question 33

Anchoring junctions bind what and are found where

Answer 33

Bind cells to each other and to ECM | Found in all tissues, especially those subject to mechanical stress

Question 34

Adherens junctions are found primarily in ____

Answer 34

epithelia

Question 35

Adherens junctions form a continuous ____ ___ and are required for _____ _____ formation and ____ ____ formation in _____

Answer 35

Adhesion belt Tight junctions Epithelial tube Morphogenesis

Question 36

Transmembrane proteins in adherens junctions and desmosomes

Answer 36

Cadherins

Question 37

Adherin junctions connect bundles of ____ filaments (_____)

Answer 37

Actin | Contractile

Question 38

Desmosomes are found primarily in _____

Answer 38

Epithelia and muscle cells

Question 39

Desmosomes contribute to

Answer 39

Tissue strength & durability

Question 40

Hemidesmosome function

Answer 40

Bind cells to ECM | Attach junctional epithelium to tooth enamel

Question 41

Transmembrane proteisn in hemidesmosomes

Answer 41

Integrins

Question 42

Focal adhesions functions

Answer 42

``` Spot-type junctions that link cell cytoskeleton to ECM Important in Cell migration Motility Differentiation Proliferation Orthodontic tooth movement ```

Question 43

How many proteins can focal adhesions contain

Answer 43

As many as 100

Question 44

Response of focal adhesions to IC or EC signals

Answer 44

They can form, change, or disappear in response (Dynamic)

Question 45

External mechanical signals are transmitted via

Answer 45

Integrin receptors in focal adhesions

Question 46

Gap junctions are found primarily in _________

Answer 46

All cells except skeletal muscle and blood cells

Question 47

Gap junction permeability

Answer 47

Allow small molecules and electrical charges to pass directly from cell to cell Varies with the identity and combination of connexins present

Question 48

Gap junction permeability regulated by

Answer 48

Intra- and extra- cellular signals

Question 49

Channels in gap junctions are called ____ and are ____ of ____ proteins

Answer 49

Connexons Hexamers Connexin

Question 50

Gap junctions main function

Answer 50

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