Exam 2 (Ch. 7-9)

Question 1

excess energy on the surface is called…

Answer 1

surface tension

Question 2

adsorption is…

Answer 2

adhesion of molecules to a solid surface

Question 3

absorption is…

Answer 3

penetration of molecules into the bulk of another material

Question 4

adsorbate within the body is composed of…

Answer 4

ions, water, and proteins

Question 5

two surface properties with largest effect on favorability of adsorption

Answer 5

hydrophobicity and charge

Question 6

protein adsorption generally (increases/decreases) with increasing hydrophobicity

Answer 6

increases

Question 7

PEG is…

Answer 7

large, flexible, and hydrophilic

Question 8

two other factors that affect adsorption are…

Answer 8

surface roughness and steric concerns

Question 9

a high degree of surface roughness can promote protein adsorption bc…

Answer 9

it can “trap” proteins in valleys

Question 10

ideal surface treatments are…

Answer 10

thin, resistant to delamination, and simple and robust

Question 11

chemical surface modifications add…

Answer 11

covalent coatings

Question 12

plasma discharge treatments (chemical surface modification) are…

Answer 12

easily prepared, sterile, free of pinhole defects…but expensive and can be contaminated

Question 13

chemical vapor deposition (CVD)…

Answer 13

exposes a sample to a mixture of gases, resulting in a coating (often pyrolytic carbon)

Question 14

sputter deposition (a kind of physical vapor deposition) has two steps…

Answer 14

energetic ions bombard the target and transfer momentum, causing ejection of some target surface atoms which strike the sample surface and form a thin film

Question 15

radiation grafting and photografting are (chemical/physical) surface modification techniques that…

Answer 15

chemical, that form surface coatings (can add hydrogels to hydrophobic surfaces)

Question 16

self-assembling molecules (SAMs) are amphiphilic and have three key regions…

Answer 16

attachment group, long hydrocarbon chain, function (polar) head group

Question 17

the driving force for assembly between the substrate material and an SAM’s attachment group is…

Answer 17

a strong exothermic reaction

Question 18

Langmuir-Blodgett film deposition is a non-covalent chemical surface modification technique where…

Answer 18

amphiphilic molecules are deposited on the surface in a Langmuir trough (versatile but unstable)

Question 19

surface-modifying additives (SMAs)…

Answer 19

spontaneously rise to the surface when added to material bulk

Question 20

conversion coating…

Answer 20

adds an oxide layer to a metallic implant (barrier to corrosion)

Question 21

lithography techniques are used for…

Answer 21

patterning (high precision, high cost)

Question 22

light microscopy yields…

Answer 22

qualitative imaging of a surface

Question 23

electron spectroscopy (ESCA) and x-ray photoelectron spectroscopy (XPS) yield…

Answer 23

spectra of atoms present with binding energy

Question 24

ATR-FTIR yields…

Answer 24

absorbance spectra

Question 25

secondary ion mass spectrometry (SIMS)

Answer 25

separates ionic species by mass, gives info on composition of top few atomic layers

Question 26

scanning electron microscopy...

Answer 26

images a surface and allows for analysis of both the X-rays and electrons emitted when it is bombarded with an electron beam

Question 27

micro-contact printing is...

Answer 27

stamping technique (patterning)

Question 28

__________ is a measure of the amount of energy in a system available for work

Answer 28

enthalpy

Question 29

__________ is a measure of the disorder of the system

Answer 29

entropy

Question 30

zwitterions...

Answer 30

carry equal but opposite charges

Question 31

______ is the amino acid that has a ring and is therefore highly inflexible

Answer 31

proline (prO)

Question 32

________ is the amino acid that can form strong disulfide bonds

Answer 32

cysteine

Question 33

after enough time, desorption becomes unlikely because...

Answer 33

all contact points would have to break simultaneously

Question 34

describe the Vroman effect

Answer 34

proteins which are smaller or in greater concentration will arrive to the surface first, but will eventually be displaced by those with greater affinity

Question 35

high performance liquid chromatography (HPLC) or adsorption chromatography...

Answer 35

beads in the stationary phase are coated with either very hydrophobic or hydrophilic polymers - analyte molecules then adsorb to the beads to varying degrees (first species out have least affinity for the column)

Question 36

normal phase chromatography

Answer 36

POLAR stationary phase, NONPOLAR mobile (more hydrophilic molecules eluted LATER)

Question 37

reversed-phase chromatography

Answer 37

NONPOLAR stationary phase, POLAR mobile phase (more hydrophilic molecules eluted FIRST)

Question 38

enzyme-linked immunosorbent assay (ELISA)

Answer 38

plates are coated with an antibody that attaches to the protein of interest, allows for quantification of the amount of protein in a solution or on a surface

Question 39

differentiated (committed) cells have

Answer 39

attained tissue-specific function

Question 40

non-differentiated (progenitor) cells are

Answer 40

uncommitted

Question 41

three types of cell contacts

Answer 41

tight junctions (nothing thru), gap junctions (some stuff thru), desmosomes (belt or spot, like stitches)

Question 42

two types of cell-ECM contacts

Answer 42

hemidesmosomes and focal adhesions

Question 43

the ECM is made up of...

Answer 43

fiber-forming elements (collagen and elastin) and filler molecules (glycoproteins and proteoglycans)

Question 44

__________ is the most abundant protein in mammals, made up of alpha chains, and is responsible for tissue tensile strength

Answer 44

collagen

Question 45

collagen --> ________ --> _________

Answer 45

fibrils, fibers

Question 46

____________ facilitates formation of hemidesmosomes and focal adhesions

Answer 46

fibronectin

Question 47

traditional cell death is called...programmed cell death is called...

Answer 47

necrosis, apoptosis

Question 48

_____ cells replicate continuously

Answer 48

labile

Question 49

stems cells are unipotent, _________, or ___________

Answer 49

multipotent, totipotent

Question 50

the ________ is the binding site on mRNA

Answer 50

anticodon

Question 51

the _____ theory is a basic cell adhesion model

Answer 51

DLVO

Question 52

__________ are finger-like extensions from a cell involved in both....

Answer 52

pseudopodia, involved in both cell spreading and migration

Question 53

____________ is directed movement in response to soluble chemical signals (requires a gradient)

Answer 53

chemotaxis (taxi)

Question 54

two types of indirect contact assays (for cytotoxicity)

Answer 54

agar diffusion assay and filter diffusion test

Question 55

_________ assays are used to determine the cytotoxicity of leachable molecules found in biomaterials

Answer 55

elution

Question 56

the ________________ is an assay that measures cell migration distance

Answer 56

capillary tube test

Question 57

assays that measure the time required for cells to migrate and close a gap are called...

Answer 57

scratch tests

Question 58

the Boyden chamber assay measures...

Answer 58

the number of cells migrating away from a given area

Question 59

PCR tests allow for evaluation of the...

Answer 59

damage to a cell's DNA

Question 60

laser confocal scanning microscopy (LCSM) allows for

Answer 60

visualization of tissues or tissue-based constructs