Dr. Mokrzan SG

Question 1

complex network of macromolecules in the extracellular space

secreted by the cells which inhabit it

Answer 1

ECM

Question 2

gives structural and organizational support to tissues, makes up a substantial part of tissue volume

Answer 2

ECM

Question 3

Collagen is _%of total body protein, and 90% of it is __

Answer 3

30% total body protein

90% of it is collagen Type I

Question 4

structure of collagen? strengthened and stabilized by __

Answer 4

triple-helical structure

stabilized by crosslinks

Question 5

Fibrillar and nonfibrillar collagens

Answer 5

fibrillar = type I,II,II,V,XI

nonfibrillar = type IV, FACIT

Question 6

Collagen is frequently remodeled, and synthesis is affected by physiologic conditions such

Answer 6

as diet or mechanical stress

Question 7

Osteogenesis/dentogenesis imperfecta is the result of a genetic mutation that causes the __in Type I collagen to be replaced by another amino acid

Answer 7

glycine

Question 8

provides flexibility and resilience to the ECM

Answer 8

elastin

Question 9

Predominant ECM molecule in blood vessels

Answer 9

elastin

Question 10

elastin is Stabilized by

Answer 10

two-way crosslinks

Question 11

Not synthesized after adolescence

Answer 11

elastin

Question 12

facilitates communication between intracellular and extracellular compartments

Answer 12

fibronectin

Question 13

fibronectin binds to __molecules on cells

Answer 13

integrin

Question 14

Important for cell adhesion, growth, migration, and wound healing

Answer 14

fibronectin

Question 15

soluble and insoluble forms of __ interact with oral pathogens

Answer 15

fibronectin

Question 16

found primarily in basal lamina, Gives structural support to the ECM

Answer 16

laminin

Question 17

Major component of basement membranes in epithelial and muscle tissues

Binds to cells, often through the integrin family of proteins

Answer 17

laminin

Question 18

the gel-formers of the ECM

Answer 18

proteoglycans

Question 19

Have many negative charges, which attract cations and water. The result is hydration of the ECM, which provides rigidity and durability.

Answer 19

proteoglycans

Question 20

Proteoglycans are __% of ECM protein, but because of their hydrophilicity, __ chains fill most of the extracellular space

Answer 20

<10%

GAG

Question 21

the major proteoglycan in the articular cartilage, proteoglycans join to form _

Answer 21

aggrecan

Question 22

•muscular dystrophies•lethal skin blistering disease epidermolysis bullosa•defects of kidney filter

Answer 22

laminin defects

Question 23

• Structure of molecules, diversity
• Can also bind growth factors, regulate enzyme activity, and act as co-receptors
• Lysosomal storage diseases

Answer 23

proteoglycans

Question 24

Specialized regions where cells are attached to each other and the ECM

Answer 24

cell junctions

Question 25

__ tissues are particularly rich in cellular junctions

Answer 25

epithelial tissues

Question 26

Cell-cell junctions found in all epithelia. Severely limit intercellular permeability and maintain cell membrane polarity (different protein components of apical and basolateral membranes)

Answer 26

tight junctions

Question 27

Formed by sealing strands anchored in the membrane | Required for active transport of solutes across the epithelial barrier

Answer 27

tight junctions

Question 28

junctions are impermeable to macromolecules, but permeability to small molecules varies greatly, depending on the number of sealing strands and the different transmembrane proteins (occludin and claudin families) that comprise them.

Answer 28

tight junctions

Question 29

Bind cells to each other and to the ECM. They are found in all tissues, especially those subject to mechanical stress.

Answer 29

anchoring junctions

Question 30

Cell-cell junction found primarily in epithelia | Form a continuous adhesion belt just below the tight junction

Answer 30

adherens junctions

Question 31

adherens junctions transmembrane proteins are __

Answer 31

cadherins

Question 32

Connect bundles of actin filaments – contractile

Answer 32

adherens junctions

Question 33

Necessary for tight junction formation and epithelial tube formation in morphogenesis

Answer 33

adherens junctions

Question 34

* Cell-cell junctions that “rivet” cells together * Found primarily in epithelia and muscle cells * Contribute to tissue strength and durability * Transmembrane proteins are cadherins

Answer 34

desmosomes

Question 35

* bind cells to the ECM * Transmembrane adhesion proteins are the integrins * Attach the junctional epithelium to the tooth enamel

Answer 35

hemidesmosomes

Question 36

spot-type junctions that link the cell cytoskeleton to the ECM • Can contain as many as 100 different proteins

Answer 36

focal adhesions

Question 37

• Dynamic: they can form, change, or disappear in response to intracellular or extracellular signals

Answer 37

focal adhesions

Question 38

focal adhesions transmit external mechanical signsl via __ receptors

Answer 38

integrin

Question 39

Important in cell migration, motility, differentiation, proliferation, and orthodontic tooth movement

Answer 39

focal adhesions

Question 40

communicating junctions found in nearly all cells except skeletal muscle and blood cells

Answer 40

gap junctions

Question 41

Gap junction permeability can be regulated by both

Answer 41

intra- and extra-cellular signals

Question 42

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

Answer 42

gap junctions

Question 43

gap junction Channels, called __, are hexamers of connexin proteins

Answer 43

connexons

Question 44

FACIT

Answer 44

fibril associated collagens with interrupted triple helices

Question 45

tight junctions are only found in

Answer 45

epithelial tissues

Question 46

hemidesmosomes are missing integrins

Answer 46

periodontal disease

Question 47

joins an actin bundle in one cell to a similar bundle in a neightboring cell

Answer 47

adherens junx

Question 48

joins the intermediate filaments in one cell to those in a neighbor

Answer 48

desmosome

Question 49

allows the passage of small watersoluble ions and molecules

Answer 49

gap junx

Question 50

anchors intermediate filaments in a cell to the basal lamina

Answer 50

hemidesomsome