Chapter 7: Interactions Between Cells And Their Environment

Front 1

Cells interact with extracellular material to form _____________

Back 1

defined tissues

Front 2

Interactions are crucial to the formation of _______________ and _______________, which are crucial for various cellular activities

Back 2

epithelial tissue and connective tissue

Front 3

The ________ is formed from carbohydrate projections from the plasma membrane

Back 3

glycocalyx

Front 4

Glycocalyx mediates _______ and ________ interactions

Back 4

cell-cell

cell-substratum

Front 5

Extracellular Matrix (ECM)

Back 5

An organisms network beyond the plasma membrane

Front 6

Basement Membrane

Back 6

Continuous sheet that underlies epithelial tissue and surrounds blood vessels

Front 7

Extracellular Matrix helps maintain ___________

Back 7

cell attachment

Front 8

Extracellular Matrix serves as substratum for ___________________

Back 8

cell migration

Front 9

Extracellular matrix forms a barrier to __________________

Back 9

macromolecules

Front 10

Collagens

Back 10

Fibrous glycoproteins found only in the Extracellular Matrix

Front 11

Collagen provides high _____ strength

Back 11

tensile

Front 12

Collagen are a trimer of __________________ wound around each other

Back 12

polypeptide chains

Front 13

Collagen molecule

Back 13

triple helix of three helical alpha chains

Front 14

Collagens provide the insoluble framework that determines ____________________ of the matrix

Back 14

mechanical properties

Front 15

Not all collagens form _______

Back 15

fibrils

Front 16

Collagen Type IV is _______, and is restricted to the basement membrane

Back 16

non-fibrillar

Front 17

Fibril Collagen Type 1

Back 17

osteogenesis imperfect - fragile bones

Front 18

Fibril Collagen Type 2

Back 18

Dwarfism

Front 19

Fibril Collagen Ehler-Danlos syndromes

Back 19

Hyperflexibility

Front 20

Fibrosis

Back 20

Overproduction of collagen in lung or liver

Front 21

Non-fibrillar (Type 4)

Back 21

Alpert Syndrome - kidney disease of the glomerular basement membrane

Front 22

Proteoglycans

Back 22

Protein-polysaccharide complex with a core protein attached to glycosaminoglycans (GAGs)

Front 23

Proteoglycans have a repeating ____________ structure

Back 23

disaccharide

Front 24

Negatively charged GAGs attract lots of cations, which in turn attract water forming a __________________________

Back 24

porous, hydrated gel

Front 25

Proteoglycans cross-linked into large matrix by ________________________

Back 25

hyaluronic acid

Front 26

Proteoglycans resist crushing forces; they __________________

Back 26

cushion cells

Front 27

Proteoglycans provide binding sides for growth hormones to protect from __________

Back 27

proteases

Front 28

Fibronectin (Fn)

Back 28

A linear array of distinct polypeptides giving it a modular structure

Front 29

Fibronectin has binding sites for other components of the ____________________

Back 29

Extracellular Matrix

Front 30

Fibronectin guides migrating cells during __________________

Back 30

embryogenesis

Front 31

Laminins

Back 31

Extracellular glycoproteins consisting of 3 polypeptide chains linked by disulfide bonds

Front 32

Laminins are found in the ____________ membrane

Back 32

Basement

Front 33

Laminins help cell migration during _____________

Back 33

development

Front 34

Dynamic Properties of the ECM

Back 34

Can be stretched during tension

Non static, constant remodeling by degradation and reconstruction

ECM materials degraded by matrix metalloproteinases (MMPs)

MMPs possibly involved in tissue remodeling, embryonic cell migration, wound healing, and formation of blood vessels

Disease states associated with MMPs:

-Arthritis, tumor progression, blood clots, and heart attacks

MMPs regulated by TIMPs (tissue inhibitor of metalloproteinases)

Front 35

Integrins

Back 35

Family of membrane proteins composed of heterodimers with alpha and beta subunits

Front 36

Integrins have a major role in integrating _________________ and ______________ environments

Back 36

extracellular and intracellular

Front 37

Integrins other role is ___________ of cells to their substratum or other cells

Back 37

adhesion

Front 38

Linkage between integrins and their ligands mediates ___________ between cells and their environment

Back 38

adhesion

Front 39

Binding of proteins to integrins is facilitated by __________________

Back 39

tripeptide RGD

Front 40

RGD required for _______________________

Back 40

platelet aggregation

Front 41

Fibrinogen

Back 41

binds to integrin in gluing platelets together

Front 42

Clot Buster Drugs

Back 42

RGD peptide acts as competitive inhibitor to Fibrinogen/Integrin interaction

Front 43

Cytoplasmic domains of integrins contain binding sites for a variety of ___________ proteins

Back 43

cytoplasmic

Front 44

Integrins make the connection between the ________ and the ______________

Back 44

ECM and the cytoskeleton

Front 45

Focal adhesions

Back 45

Scattered discrete sites for cell adhesion to their substratum in vitro

Front 46

Focal adhesions may act as a type of __________ structure

Back 46

sensory

Front 47

Focal adhesions are implicated in cell ________________

Back 47

locomotion

Front 48

Focal adhesions are sites where cells ____________________________________________________________________________________________________

Back 48

adhere to their substratum and send signals to the cell interior

Front 49

Hemidesmosomes

Back 49

Basal attachments of epithelial cells to the basement membrane in vivo

Front 50

Hemidesmosomes contains a dense plaque with filaments consisting of __________

Back 50

keratin

Front 51

Keratin filaments are linked to the ECM by __________________________________

Back 51

membrane-spanning integrins

Front 52

Focal adhesions generate force that ____________________

Back 52

deforms collagen substratum grid pattern

Front 53

Bullous Pemphigoid

Back 53

Autoimmune disease, antibodies produced against plaque proteins

Front 54

Epidermolysis Bullosa

Back 54

Genetic disease for hemidesmosomal proteins

Front 55

Cells have surface-recognition sites that maintain ______________

Back 55

organization

Front 56

Selectins

Back 56

Family of integral membrane glycoproteins that bind to sugars on the surface of cells

Front 57

Selectins contain a __________, a ____________, and a __________________

Back 57

small cytoplasmic domain, single membrane-spanning domain, and large extracellular segment

Front 58

3 Types of Selectins

Back 58

E-Selectin - on endothelial cells

P-Selectin - on platelets and endothelial cells

L-Selectin - on white blood cells

Front 59

Immunoglobulin Superfamily (IgSF)

Back 59

Most proteins are involved in immune functions

Most IgSF molecules mediate interaction of lymphocytes with cells required or immune response

Front 60

Some IgSF molecules mediate adhesion between non-immune cells:

Back 60

VCAM (vascular cell-adhesion molecule)

NCAM (neural cell adhesion molecule)

L1 (neural development)

Front 61

Cadherins

Back 61

Glycoproteins that mediate CA^2+ - dependent cell-cell adhesion

Front 62

Cadherins join cells of similar types to one another by ______________________ to the same cadherin present at the surface of the neighboring cell

Back 62

preferential binding

Front 63

Cadherins family of at least 30 related glycoproteins for cell adhesion

Back 63

E-cadherin (epithelial)

N-cadherin (neural)

P-cadherin (placental)

Front 64

Cadherins also involved in transmitting signals from __________ to the _____________

Back 64

ECM to the cytoplasm

Front 65

Cadherins mediate many of the changes in adhesive contacts during embryonic development by forming _______________________________________________

Back 65

epithelial-mesenchymal transition (EMT)

Front 66

During embryogensis, cells ______ and _____ specific adhesive properties

Back 66

gain and lose

Front 67

Cadherins epithelia: __________________

Cadherins mesenchyme: ________________

Back 67

tight associations

loose associations

Front 68

Adherens junctions

Back 68

Form belts near apical surface called junctional complex

Front 69

Cells of an adherens junction held together by ____________________ linkages

Back 69

calcium-dependent

Front 70

The cytoplasmic domain of cadherin molecule is connected to the actin filaments of the cytoskeleton by linking ____________

Back 70

proteins, including beta catenin

Front 71

Beta-catenin has also been implicated as a key element in a signaling pathway leading from the cell _____ to the cell _______

Back 71

surface, nucleus

Front 72

Desmosomes

Back 72

Disk-shaped adhesive junctions between cells

Front 73

Desmosomes contain _________ that link the 2 cells across a narrow gap

Back 73

cadherins

Front 74

Cadherins of desmosomes have different domain structures: __________ and ______________

Back 74

desmogleins and desmocollins

Front 75

Pemphigus vulgaris

Back 75

Abs against desmogleins; loss of cell-cell containt/blistering

Front 76

Transfer of information across plasma membrane

Back 76

Transmembrane Signaling

Front 77

Integrins and cadherins can transmit signals from the ______________ to the ______________

Back 77

extracellular environment to the cytoplasm

Front 78

The binding of an integrin with its ligand can ______________________ such as changes in growth potential

Back 78

induce a response

Front 79

Tight junctions

Back 79

Specialized contacts between epithelial cells

Front 80

Tight junctions are located at ______________________________________________________________

Back 80

very apical end of the junctional complex between adjacent cells

Front 81

Tight junctions serve as a barrier to free diffusion of water and solutes from the ____________________________

Back 81

extracellular compartment

Front 82

Some tight junctions are permeable to __________________________________

Back 82

specific ions or solutes

Front 83

Occludins

Back 83

proteins found in Tight Junctions

Front 84

Claudins

Back 84

form the major structual component of tight junctions, and may account for selective differences in tight junction permeability

Front 85

Claudin-16

Back 85

expressed in kidney tubule; abnormal claudin-16 makes tubule impermeable to Mg+2; excreted not reabsorbed

Front 86

Claudin-1

Back 86

KO mice die from dehydration from uncontrolled water loss

Front 87

Gap Junctions

Back 87

sites between animal cells for intercellular communication

Front 88

Gap junctions composed entirely of membrane protein _______________

Back 88

connexin

Front 89

Connexins are organized into a complex called ____________

Back 89

connexon

Front 90

Gap-junction intercellular communication allows the passage of ________________________

Back 90

low-weight molecules

Front 91

Gap junctions can allow integration of activites of individual cells into a _______________

Back 91

functional unit

Front 92

Compatibility differences between connexins either _______ or _______ communication between different cells

Back 92

promote or prevent

Front 93

Tunneling nanotubes

Back 93

observed in cells growing in culture

cells connected to one another by a thin tubular process capable of carrying materials between cytoplasm of the neighboring cells

can transmit viral particles and prions

Front 94

Plasmodesmata

Back 94

cytoplasmic channels passing through cell walls of adjacent plant cells

Front 95

Plasmodesmata are lined by _____________

Back 95

plasma membrane

Front 96

Plasmodesmata contain a central structure, the __________________

Back 96

desmotubule

Front 97

Plasmodesmata serve as sites of ________________________

Back 97

cell-cell communication

Front 98

Cell walls

Back 98

provide plants protection against mechanical abrasion, pathogens, and osmotic stress

Front 99

Cells walls fibrous component is ________

Back 99

cellulose

Front 100

Cellulose is organized into _______, which provide rigidity to the cell wall

Back 100

microfibrils

Front 101

The matrix of the cell wall contains _________, ___________, and __________

Back 101

hemicelluloses, pectins, and proteins

Front 102

Cell walls arise as a ______________ that forms between the plasma membranes of newly formed daughter cells

Back 102

cell plate

Front 103

The walls of growing cells are ____________ and allow flexibility lacking in the thicker ____________ of mature cells

Back 103

primary walls

secondary walls

Front 104

Cellulose molecules are polymerized at the ____________________

Back 104

cell surface

Front 105

Glucose is added to the end of a growing cellulose molecule by ________________

Back 105

cellulose synthase

Front 106

Materials of the matrix are synthesized in the cytoplasm and carried to the ________________________________

Back 106

cell surface in secretory vesicles