crossing membranes Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

how do solutes cross membranes?

A

simple diffusion
facilitated diffusion
active transport

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

what molecules can move freely through the membrane?

A

small uncharged molecules

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

what is simple diffusion?

A

unassisted movement down the gradient

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

what is facilitated diffusion?

A

protein mediated movement down the gradient (no energy, only high-low)

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

what are the two main types of facilitated diffusion?

A

channels and carriers (both proteins)

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

how do carrier proteins work?

A

they alternate between two conformational states, can transport one or two molecules each

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

what are the two types of carrier proteins?

A

antiporters (two molecules in different directions) and symporters (two molecules in same direction)

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

how do channel proteins work?

A

forming hydrophilic transmembrane channels

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

what are the three types of channel proteins?

A

ion channels (specific)
porins (unspecific)
aqauporins (water)

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

what opens ion channel gates?

A

voltage
ligand
temperature
pressure

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

what is an example of an ion channel?

A

potassium channels - potassium interacts with oxygen while sodium are smaller and can’t interact with oxygen so cant make it through

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

why is passing ions important?

A

it changes the polarization which cells can read and use it as an intracellular signal

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

what do ligand gates ion channels do?

A

convert chemical signals into the cell

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

what do voltage gated sodium channels do?

A

transmit signals in a wave throughout the nervous system

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

what are porins?

A

transmembrane proteins allowing rapid passage of various solutes

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

what is the charge of ATP?

A

negative

17
Q

what are VDACs?

A

voltage-dependent anion channels that mediate exchange of negatively charged metabolites (ATP from mitochondria to cytoplasm)

18
Q

what are aqauporins?

A

transmembrane channels that allow rapid passage of water

19
Q
A