Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Applied Biochemistry > Membrane Structure and Function > Flashcards

Membrane Structure and Function Flashcards

1
Q

outer leaflet

A

exposed to the external side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

inner leaflet

A

exposed to the cytoplasmic side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

leaflets can vary between

A

different parts of the membrane

phospholipid content, protein content, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the phospholipid bilayer undergoes

A

natural oscillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

glycerol backbone contains

A

3 OH groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the 3 OH groups of glycerol are sites for

A

side chain attachment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the glycerol backbone is attached to

A

fatty acid tails

polar phosphate head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

sphingosine backbone is usually O-linked to a

A

charged group and amide-linked to an acyl group, such as a fatty acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when you have a FA attached to the glycerol=

A

nonpolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when you have a phosphate attached to the glycerol=

A

polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

diffusion in saturated lipids

A

slow because it is tightly packed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

diffusion in mixed saturated and unsaturated lipids

A

quick because there is spacing created because of the kinks and is therefore much more open and molecules can move quicker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

membrane phospholipid bilayers serve as

A

semipermeable membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

charged molecules cannot diffuse through

A

the lipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

O2, N2, H2O, and CO2 can

A

diffuse rapidly across the lipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

glycine and other amino acids cannot

A

diffuse across membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

hydrophobic compounds can

A

diffuse across membranes

ex. estrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

lipid contents of the plasma membrane are distributed

A

asymmetrically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

lipid components found outside of the cell (3)

A

sphingomyelin
glycolipid
phosphatidylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

lipid components found ion the cytoplasmic leaflet (3)

A

phosphatidylserine
phosphotidylinositol
phosphatidylethanolamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

cholesterol distribution

A

symmetrically distributed amongst the outer and inner leaflet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

phospholipids can be cleaved into products that function as important

A

intracellular second messangers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

PIP2 is cleaved by phospholipase C to form

A

IP3
DAG
important in intracellular signaling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

when phospholipids are dispersed in water, they naturally for

A

vesicles

multilammellar or monolayer/unilammellar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what happens when water and oil are mixed rapidly?

A

it is initially cloudy because vesicles are forming. eventually they will settle and separate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

liposomes are

A

artificially prepared vesicles composed of a lipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

liposomes can be used to

A

administer and transport nutrients and pharmaceutical drugs in the body

28
Q

homing peptides

A

can target molecules on the outside

29
Q

liposomes have a protective layer against

A 
immune destruction 
(prevents immune interaction and destruction)
30
Q

liposomes contain a (6)

A
  • protective layer against immune destruction
  • DNA
  • homing peptide
  • drug crystalized in aqueous fluid
  • lipid-soluble drug in bilayer
  • lipid bilayer
31
Q

pfizer and moderna mechanism of action

A

liposome contains RNA that codes the spike protein. spike protein will attach to the virus, produce spike protein, and the body will create an immune response to destroy the virus

32
Q

bottom line of liposome mechanisms

A

many drugs use liposome technology to treat diseases

33
Q

the alpha helix is a common structural feature of

A

transmembrane regions of integral membrane proteins

34
Q

amino acids that make up the alpha helix are

A

uncharged to interact with the inner leaflet

35
Q

membrane protein functions (4)

A

cell-cell contact/adhesion
receptor signaling systems
pores and channels (transport)
enzymes

36
Q

absorption and synthesis of cholesterol is important and much is known about

A

hereditary problems

37
Q

other components of the plasma membrane (2)

A

cholesterol

triglycerides

38
Q

FRAP shows us that

A

proteins move within the plasma membrane

39
Q

FRAP

A

protein is labeled with fluorescent dye, shine a laser beam on the plasma membrane, fluorescence is lost, but overtime, this area regains fluorescence because proteins move within this region that the laser bleached

40
Q

flippase

A

ex. PS, PE

from the outer to the inner leaflet

41
Q

floppase

A

ex. PC, SL

from the inner to the outer leaflet

42
Q

flippase and floppase require

A

ATP because they move against a concentration gradient

43
Q

scramblase

A

ex. cholesterol
transfers between the inner and outer leaflet
does not require ATP

44
Q

scramblase mechanism

A

lipid bilayer of the ER
phospholipid synthesis adds to the cytosolic half of the bilayer
scramblase catalyzes flipping of phospholipid molecules
symmetric growth of both halves of the bilayer

45
Q

flippase mechanism

A

asymmetric lipid bilayer of the plasma membrane
delivery of new membrane by exocytosis
flippase catalyzes flipping of specific phospholipids to cytoplasmic monolayer

46
Q

lipid rafts are specialized domains predominately within plasma membranes of cells which

A

organize membrane proteins and glycolipids in groupings, having functional implications in terms of receptor trafficking, neurotransmission, and membrane fluidity

47
Q

lipid rafts move as

A

unit instead of individual parts

48
Q

lipid rafts differ from the plasma membrane as a whole by being enriched in

A

cholesterol and sphingolipids

49
Q

lipid rafts tend to be resistant to

A

dissociation by detergents which can freely dissociate the fluid membrane sections

50
Q

caveolae

A

invaginations of the plasma membrane

51
Q

caveolae form from

A

lipid rafts

52
Q

it has been proposed that lipid rafts play a role in cell signaling events for the (3)

A

b-cell antigen receptor
t-cell antigen receptor
IgE receptor

53
Q

ultracentrifugation

A

used to separate different membrane bound compartments like mitochondria and nucleus

54
Q

density gradient ultracentrifugation

A

used to separate biological membranes containing lipids (and having lower densities) from proteins (having higher densities)

55
Q

electron microscopy

A

An EM has greater resolving power than a light microscope and can reveal the structure of smaller objects because electrons have wavelengths about 100,000 times shorter than visible light photons. They can achieve better than 50 pm resolution and magnifications of up to about 10,000,000x whereas ordinary, non-confocal light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications below 2000x.

56
Q

fluorescence microscopy

A

uses fluorescence and phosphorescence instead of, or in addition to, reflection and absorption to study properties of organic or inorganic substances

57
Q

atomic force microscopy

A

very high-resolution type of scanning probe microscopy, with demonstrated resolution on the order of fractions of a nanometer, more than 1000x better than the optical diffraction limit

58
Q

cell fractionation mechanism

A

due to centifugational force, large or verse dense particles move toward the bottom of a tube and form a pellet
cell structures can be separated into various fractions by spinning the suspension at increasing revolutions per minute. membranes and organelles from the resuspended pellets can then be further purified by density gradient centrifugation

59
Q

detergents solubilize

A

membranes

60
Q

detergent mechanism

A

detergent positions itself within the membrane so the membrane falls apart. it encapsulates the lipids so they cannot come back together

61
Q

freeze faction is used to

A

split apart the membrane

62
Q

cantilever deflection can trace

A

the topography, where proteins are located, etc

63
Q

virus fusion to the plasma membrane

A

enveloped virus attaches to the cell membrane of recipient cell via receptors, and receptors on the surface of the virus, followed by fusion where the envelope blends with the cell membrane and releases its contents (genome) into the cell

64
Q

enveloped viruses containing human pathogens

A 
DNA viruses (ex. herpes)
RNA viruses (ex. corona)
retroviruses (ex. HIV)
65
Q

coronavirus

A

spike protein binds to receptor on a mammalian cell to trigger fusion

66
Q

ACE2 concentrates on the

A

airway epithelium cells

67
Q

why does washing hands with soapy water work to reduce/ prevent infection?

A

using detergent to break down a membrane so viruses cannot bind to the membrane and fuse

Applied Biochemistry (52 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions