Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

bio > b2.1 membranes and membrane transport > Flashcards

b2.1 membranes and membrane transport Flashcards

(66 cards)

Start Studying
1
Q

basis of cell membranes

A

lipid bilayers

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

hydrophilic

A

molecule is attracted to water

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

hydrophobic

A

molecule is repelled by water

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

amphipathic + eg

A

both hydrophilic and hydrophobic
eg. phospholipids

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

labelled diagram of the plasma membrane

A

ipad notes

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

functions of membrane proteins [6]

A

Transport
Receptors
Anchorage
Cell recognition
Intracellular joining
Enzyme activity
TRACIE

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

stucture of glycoproteins

A

carbohydrates structure linked to protein in membrane

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

glycoproteins location + reason

A
  • on the extracellular side of the membrane
  • used for cell adhesion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

structure of glycolipids

A

carbohydrates linked to lipid in membrane

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

glycolipids location + reason

A
  • on the extracellular side of the membrane
  • used for cell recognition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

temperature property of unsaturated fatty acids [3]

A

low melting point
- membranes are fluid
- flexible at temperatures experienced by a cell

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

temperature property of saturated fatty acids

A

higher melting points
- make membranes stronger at higher temperatures

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

definition of endocytosis + eg

A

cell membrane can change shape slightly to form vesicle and budded off form cell surface and enter the cytoplasm as vesicle
eg. phagocytosis

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

definition of exocytosis + eg

A

vesicles can fuse with the cell membrane to export substance out of the cell
eg. secretion of enzymes

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

example of a neutransmitter-gated ion channel

A

nicotinic acetycholine receptors

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

example of voltage-gated channels

A
  • sodium and potassium channels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

function of cell-adhesion molecules (CAMs)

A
  • used for different types of cell to cell junction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does the membrane fluidity depend on

A

the fatty acid composition of the phospholipids

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

saturated fatty acid bonds

A
  • single bonds
  • straight chain structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

straight chain structure allows for…

A
  • more stability due to more intermolecular forces
  • reduces fluidity, flexibility and permeability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

unsaturated fatty acid bond

A
  • double bonds
  • results in kinks within the structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

effect of the structure of the unsaturated fatty acid

A
  • kinks weakens the intermolecular forces -> more fluidity, flexibility and permeability in the cell membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

homeoviscous adaptation can occur when

A

the cell membrane lipid composition to maintain adequate membrane fluidity

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

what happens to the composition of the phospholipid fatty acids when temperature decreases

A
  • become more unsaturated in order to maintain homeoviscosity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
membrane lipids in cold conditions
becomes more unsaturated during acclimatisation - needs to maintain fluidity and permeability to allow material exchange on cell surface - cold temperature will reduce cell membrane's permeability
26
diagram of saturated fatty acid
no double bonds
27
diagram of unsaturated fatty acid
notes
28
cholesterol molecule: which parts are hydophilic and hydrophobic
OH- hydrophilic everything else- hydrophobic
29
how is cholesterol imbedded in the fluid mosaic model
head to head
30
why is membrane's fluidity important for endocytosis and exocytosis
- needed to transport bulk substance using a vesicle eg. neurotransmitter - vesicle has same structure as phospholipid: vesicle can fuse with the cell membrane without breaking the cell membrane
31
what do endocytosis and exocytosis require
energy
32
endocytosis
cell membrane can change shape slightly to form vesicle and budded off form cell surface and enter the cytoplasm as vesicle
33
exocytosis
vesicles can fuse with the cell membrane to export substance out of the cell
34
annotated diagram of endocytosis
notes
35
annotated diagram of exocytosis
notes
36
nicotinic acetylcholine receptors presented at
skeletal neuromuscular junctions
37
acetylcholine
neurotransmitter - act as a ligand in the ligand-gated ion channel
38
function of sodium potassium pump
helps maintain resting membrane potential
39
how does the lipid bilayer act as a barrier
hydrophobic hydrocarbon chains- low permeability to large molecules + hydrophilic particles eg. ions, polar molecules
40
what can go through using simple diffusion + examples
1. small molecules 2. soluble molecules 3. non-charged molecules eg. oxygen, carbon dioxide
41
location of integral protein
embedded in one or both lipid layers of a membrane
42
location of peripheral proteins
attached to one or other surface of the bilayer
43
movement of water molecules across membranes by osmosis and role of aquaporins
- random movement of particles - impermeability of membranes to solutes - differences in solute concentration
44
how structure of channel proteins makes membranes selectively permeable
allows specific ions to diffuse through when channels are open but not when they are closed
45
pumps use...
energy from ATP to transfer specific particles across membranes so they can move particles against a concentration gradient
46
what allows selective permeability in membranes [2]
1. facilitated diffusion 2. active transport
47
why is simple diffusion not selective
depends only on the size and hydrophilic/phobic properties of particles
48
function of cholesterol [3]
1. acts as a modulator of membrane fluidity 2. stabilises membranes at higher temperatures 3. maintains impermeability to hydrophilic particles eg. sodium and hydrogen ions
49
how does voltage-gated sodium channels only allow sodium to go through?
- diameter - negatively charged
50
what is essential for diffusion
concentration gradient
51
facilitated diffusion
passive movement of a particle across a cell membrane via a channel protein
52
processes in nerves that require a membrane protein
1. active transport of sodium 2. propagation of an action potential 3. binding of neurotransmitter
53
phospholipid structure
- hydrophilic head made from phosphate and glycerol - 2 hydrophobic tails made from fatty acids
54
what are phospholipids held together by
hydrophobic interactions
55
how are phospholipid layers stabilised
by interaction of hydrophilic heads and surrounding water
56
why is fluidity important in the plasma membrane
important in breaking and remaking membranes eg. endocytosis, exocytosis
57
what cannot use simple diffusion [3]
1. large molecules 2. charged molecules 3. non-soluble eg. water, glucose
58
features of the fluid mosaic model [4]
- flexible, adaptable and in motion - have freedom of movement - individual phospholipids are attracted to each other by weak attraction - cumulative effect: very strong membrane
59
how do pump proteins work
- molecule binds to the active site of the pump - ATP transfers phosphate to the protein - results in conformational change in the shape of the protein pump - molecules is pushed to the other side of the membrane
60
voltage-gated sodium channel used + found in
used in: facilitated diffusion found in: neurons
61
how does nicotinic acetylcholine receptor work + diagram
1. acetylcholine binds to it 2. sodium comes in: voltage to ard -50 mV - more sodium go in - new action potential created 3. impulse continues - nicotine can also bind and open the receptor
62
what is the healthiest type of fatty acid
monosaturated cis fatty acid - bends
63
how does cholesterol cause the membrane to be more fluid
- forces a gap between the membrane - moves phospholipid away form each other to ensure that theyre not too closely packed
64
non-polar means its hydrophilic/hydrophobic?
hydrophobic
65
proximal convoluted tubule
how glucose goes through and comes back 1. sodium potassium pump generates low sodium concentration 2. low Na+ concentration is generated inside the cell 3. higher Na+ concentration in the lumen, this allows Na+ to diffuse into the cell using the sodium-dependent glucose co-transporter 4. since glucose is co-transported into the cell, the cell has a higher glucose concentration 5. glucose will diffuse through the glucose channel proteins and back into the blood 6. this is known as indirect active transport
66
what happens when an action potential reaches motor end plates
neurotransmitter is released

bio (40 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions