Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cell and Molec > Membrane Structure > Flashcards

Membrane Structure Flashcards

1
Q

Where are hydrophobic tails in the cell membrane?

A

The middle

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

Where are polar head groups in the cell membrane?

A

The outside

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

How much of the membrane is proteins?

A

~50%

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

What is an amphiphilic molecule?

A

Has both hydrophobic and hydrophilic properties

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

What are polar head groups made of?

A

Choline, phosphate, glycerol at the top

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

What are hydrophobic tails of the lipid bilayer made of?

A

Fatty acids (unsaturated, saturated)

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

Difference between unsaturated and saturated?

A 
Saturated = no double bonds
Unsaturated = double bonds

Unsaturated less likely to freeze

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

How many common phospholipids are there?

A

Four

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

What’s different between the phospholipids?

A

Charge, tail length, what’s on the head

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

How many sections are there of the polar head and which is most charged?

A

3, they could all be charged

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

What is the purpose of cholesterol?

A

Stops hydrocarbon chains from freezing, makes membrane less permeable

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

How does cholesterol attach to lipids?

A

Polar head group of cholesterol lines up with lipids

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

What happens if there’s too much cholesterol?

A

Things can’t get in and out of the cell

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

Why can the membrane act as a fluid?

A

Lipids can rotate, diffuse, or flex (twist)

But they barely ever flip-flop

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

Is there the same amount of lipid in each cell membrane?

A

No, composition varies a ton depending on the membrane

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

How much cholesterol do bacteria have?

A

None

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

If you do in situ hybridization on a membrane, will the components be distributed randomly?

A

No, components of lipids are organized

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

What is a lipid raft?

A

Microdomain in membrane that concentrates membrane proteins

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

What are glycolipids useful for?

A

Attaching cells together

Can be charged (alter electrical field)

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

You fuse a mouse and human membrane together with mouse in one area. What happens?

A

Membrane proteins diffuse, and all the membrane proteins are intermixed

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

How do you measure protein diffusion?

A

FRAP

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

What does FRAP stand for?

A

Fluorescent recovery after photobleaching

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

How does FRAP work?

A

Destroy (bleach) area with laser > measure how long it takes to recover

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

How can membrane proteins interact with the membrane?

A

Interact with protein embedded in membrane

Go through membrane

Get stuck in membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are integral membrane proteins?
They go through membrane
26
What are lipid-anchored proteins?
They bind to lipid molecules
27
What are lipid-anchored proteins?
They bind to lipid molecules
28
What do you need to see on a hydropathy plot to determine if a protein is an integral membrane protein?
Hydrophilic properties - many transmembrane domains
29
Is + or - on a hydropathy plot hydrophilic?
+ (Going up)
30
What's in an aquaporin?
2 alpha helices go halfway through lipid bilayer
31
What common domain does an integral membrane protein have?
Alpha helix, has hydrophilic amino acids which go through hydrophobic core
32
What does 'multipass' in multipass transmembrane protein mean?
The protein passes through the membrane multiple times
33
What happens as a multipass transmembrane protein fold?
Lipid molecules get displaced as protein folds in closer to itself
34
What are porins?
Structures beta barrels create that let things through membrane
35
What does a beta barrel look like?
A bunch of beta sheets overlapping
36
What is the periplasm?
Space in between inner and outer membrane
37
Where are carbohydrates?
Coat the extracellular side of the cell membrane
38
What's the function of the carbohydrate layer?
Protect it from mechanical forces, chemicals, etc Cell recognition
39
What's the function of the carbohydrate layer?
Protect it from mechanical forces, chemicals, etc Cell recognition
40
What are detergents?
Small amphiphilic molecules
41
What are micelles?
Heteromeric vesicle-like structures that detergents form
42
Why use detergents to study membrane proteins?
Detergents grab proteins, mess with the lipid bilayer, and bring the proteins into solution
43
How would you study a Na+/K+ pump?
Solubilize membrane proteins with detergent Remove detergent Make your own membrane outside of the cell
44
What properties does a detergent need to be to grab a transmembrane protein without hurting it?
Nonionic, mild
45
How were ATP synthases first studied?
Using mild detergents to bring them out of membrane
46
How many domains do sperm cells have? why relevant?
3. Shows there are distinct domains with distinct proteins
47
What (generally) laterally immobilizes membrane proteins?
Protein-protein interactions (e.g. stick them there) interactions with other cells,
48
What types of molecules get across the membrane easily?
e.g. CO2, O2, N2 (hydrophobic molecules)
49
How easily can water get across?
Kinda
50
Can glucose/sucrose get across easily?
No, but a few do
51
Can ions get through a cell membrane?
absolutely not
52
What generally guides how easily a molecule crosses a membrane?
hydrophilicity
53
How do membrane-impermeable molecules get across a membrane?
Solute transporter proteins
54
What is the difference between transporter vs channel proteins?
Transporter = impermeable molecules bind, then they change conformation Channel = they're just tunnels for impermable molecules
55
What sources of energy can drive active transport?
ATP, light, coupled molecules
56
What's a coupled transporter?
e.g. 3na+ with 2 K+
57
What's a uniporter?
One molecule goes through one direction
58
What's a symporter? (coupled transport)
A molecule and co-transported ion go through membrane the same way
59
What's an antiporter? (coupled transport)
Two molecules go through membrane the opposite way
60
Take-home message for transport proteins?
They can be asymmetrically distributed in the membrane to cause specific planned movement

Cell and Molec (21 decks)

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