Extracellular Matrix- Cell Biology

Front 1

Starlings law of capillaries

Back 1

the volume of fluid and solutes reabsorbed is approximately the volume filtered

Front 2

glycosaminoglycans (GAGs)

Back 2

long, inflexible, unbranched polysaccharides w/ amino sugar which are negative and have a slippery texture

Front 3

aggrecan

Back 3

proteoglycan expressed in cartilage with keratan sulfate and chondroitin sulfate as the GAGs

Front 4

perlecan

Back 4

proteoglycan found with all cells making basal lamina that is made with heparan sulfate

Front 5

RGD sequence

Back 5

simple 3-peptide sequence that is the integrin binding sites of many adhesive proteins

Front 6

fibronectin

Back 6

large glycoprotein dimer with binding sites for extracellular components and integrins. The main product of fibroblasts. Involved in adhesion of cells to ECM

Hint 6

None

Front 7

laminin

Back 7

large glycoprotein composed of 3 large polypeptide chains with binding sites for heparan sulfate, type IV collagen, entactin and PM. Located in the Basal Lamina

Front 8

Entactin

Back 8

glycoprotein that binds to laminin and type IV collagen in the basal lamina

Front 9

Type I Collagen

Back 9

most common collagen; secreted by fibroblasts and provides tensile strenth in connective tissues

Front 10

Type II Collagen

Back 10

fill the extracellular matrix of cartilage

Front 11

Type III Collagen

Back 11

called reticular fibers; highly glycosylated collagen that forms thin fibers

Front 12

Type IV Collagen

Back 12

Sheets that surround organs and epithelia. Found in the basal lamina and external lamina for support and filtration

Front 13

Type VII collagen

Back 13

anchoring collagen found in epidermal-dermal junctions that links type IV collagen of the basal lamina to underlying connective tissue

Front 14

procollagen peptidase

Back 14

protein on E-surface of PM that cleaves registration peptides from procollagen to form tropocollagen

Front 15

propeptides or registration peptides

Back 15

guide the formation of triple helical structure and prevent intracellular formation of collagen fibers

Front 16

lysyl oxidase

Back 16

forms covalent crosslinks between tropocollagen molecules and tropoelastin molecules

Front 17

fibrillin

Back 17

glycoprotein distributed mainly as microfibrils on the elastic fiber surface

Front 18

basal laminae

Back 18

mats of specialized ECM (mostly type IV collagen) that underlie all epithelial cell cheets and tubes and surround individual muscle, fat and schwann cells

Front 19

lamina rara

Back 19

layer of basal lamina adjacent to basal PM and made of heparan sulfate (perlecan)

Front 20

lamina densa

Back 20

electron dense layer of basal lamina just beneath the lamina rara. Made mostly of type IV collagen

Front 21

lamina reticularis

Back 21

3rd layer of basal lamina that isn't always present. Connects the basal lamina to connective tissue below and composed of type III collagen

Front 22

What is the principle ECM producing cell

Back 22

fibroblast

Front 23

3 kinds of extracellular macromolecules

Back 23

glycosaminoglycans (GAG) and proteoglycans, fibrous protein (collagen and elastin) and adhesive glycoproteins (fibronectin and laminin)

Front 24

Examples of highly specialized ECM structures

Back 24

cartilage, tendons, bone, teeth and basal lamina

Front 25

components of ECM

Back 25

fibers (structural or adhesive) and ground substance

Hint 25

None

Front 26

five sulfated GAGS

Back 26

keratan sulfate, heparan sulfate, chondratin 4 and 6 sulfate, and dermatan sulfate

Front 27

what are usually linked to proteins to form proteoglycans

Back 27

sulfated GAGs

Front 28

proteoglycan function

Back 28

resist compression, retard rapid movement of microorganisms and metastatic cells, form molecular filters, binding sites for signaling molecules (and impede or enhance their function)

Front 29

what mediates the cells ability to adhere to components of the ECM?

Back 29

adhesive glycoproteins

Front 30

3 major adhesive glycoproteins

Back 30

fibronectin, laminin and enactin

Front 31

where is laminin found?

Back 31

basal lamina

Front 32

fibrillar collagens

Back 32

types I, II, and III

Front 33

What are the four major amino acids in collagen

Back 33

Pro, Gly, Hyp, Hyl

Front 34

functions of Type III Collagen

Back 34

1) support for capillaries, small nerves and muscle 2)component of basement membrane 3) main stromal fibers for myeloid and lympoid tissues and glands

Hint 34

None

Front 35

three classes of collagen

Back 35

fibrillar, sheet forming, and anchoring

Front 36

what is the secretory product of fibroblasts?

Back 36

procollagen

Front 37

Why does procollagen go straight to the Plasma membrane?

Back 37

has no sorting signal

Front 38

What type of secretion is responsible for transporting procollagen?

Back 38

constituitive

Front 39

what gives tropoelastin its elasticity

Back 39

lysyl oxidase crosslinks

Front 40

what do dark bands correspond to in negatively stained collagen fibrils?

Back 40

gap-zones

Front 41

what do light bands correspond to in negatively stained collagen fibrils

Back 41

zones of complete overlap

Front 42

what is the spacing between zones of complete overlap in collagen fibrils?

Back 42

67 or 64 nm

Front 43

what four amino acids is elastin rich in?

Back 43

pro, gly, desmosine, and isodesmosine

Hint 43

None

Front 44

what are elastic fibers composed of

Back 44

elastin and fibrillin

Front 45

what is elastin secreted as?

Back 45

tropoelastin and the fibrillin framework

Front 46

Locations of elastin fibers

Back 46

1) connective tissue 2) vocal cords 3)elastic ligaments 4) elastic cartilages 5) muscle layer of all blood vessels except capillaries

Front 47

What synthesizes basal laminae

Back 47

the cells that lie on it

Front 48

what is the function of the basal laminae

Back 48

1) cell polarity; 2) influence metabolism; 3)organize protein in the PM 4) induce differentiation 5) highways for cell migration

Front 49

composition of basal lamina

Back 49

type IV collagen + heparan sulfate proteoglycans + laminin + entactin

Front 50

What don't cross the basal lamina in normal healthy cells?

Back 50

blood vessels

Front 51

what are the principle PM receptors for binding cytoskeleton to ECM proteins?

Back 51

integrins

Front 52

how is lamina densa tethered to underlying ct in some multilayered epithelial cells

Back 52

anchoring fibrils of collagen VII

Front 53

Non-sulfated GAG

Back 53

hyaluronic acid