Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

D1 Spring - Physiology > 1/23: Cell Membrane, Membrane Transport, and Membrane Potential III > Flashcards

1/23: Cell Membrane, Membrane Transport, and Membrane Potential III Flashcards

(67 cards)

Start Studying
1
Q

What are the two mechanisms of membrane transport?

A
  1. Passive transport
  2. Active transport
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Does passive transport have energy?

A

No

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

How do substances move on a gradient in passive transport?

A

Down gradients (high to low; ΔC, ΔP, or ΔE)

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

Does active transport require energy?

A

Yes

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

How do substances move on a gradient in active transport?

A

Up gradients (low to high)

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

What are types of passive transport?

A

Diffusion
Osmosis
Bulk flow

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

What are types of active transport?

A

Active transporters
Bulk (vesicular) transport

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

What are things to consider when discussing passive transport?

A

Random thermal motion
Rate of movement

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

What is random thermal motion?

A

Molecules in a fluid are continuously and randomly bouncing around

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

What is rate of movement directly/inversely proportional to?

A

Directly: T (temperature)
Inversely: M (mass)

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

What is diffusion?

A

Movement of substances other than water down a gradient (ΔC, ΔP, or ΔE; high to low)

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

When does net movement stop in diffusion?

A

At equilibrium

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

During diffusion, random movement is ______

A

Continuous & substance specific

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

Passive transport moves the system towards ________

A

Equilibrium

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

Describe how the mass and heat flow model works

A

↑ driving force; – resistance: ↑ mass/energy flow
↓ driving force; – resistance: ↓ mass/energy flow

– driving force; ↑ resistance = ↓ mass or energy flow
– driving force; ↓ resistance = ↑ mass or energy flow

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

What can the mass and heat flow model be used to describe?

A

Diffusion
Osmosis
Blood flow through blood vessels
Air flow through airways
Capillary exchange
etc

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

Which line represents the net flux across the membrane with higher permeability?

A

Purple -
More net flux = ↓ resistance, ↑ membrane permeability = can cross membrane at a higher rate

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

What are the two different types of diffusion?

A
  1. Simple diffusion
  2. Facilitated diffusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What substances use simple diffusion?

A

Hydrophobic/lipophilic substances
ex: fatty acids, ethanol

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

What substances use facilitated diffusion?

A

Hydrophilic/lipophobic substances

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

How do substances move when using simple diffusion?

A

Directly through phospholipid bilayer
- slower
- unregulated

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

How do substances move when using facilitated diffusion?

A

Require membrane channels or carriers because can’t pass bilayer
- faster
- unregulated (specificity, saturation, competition)

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

Does simple or facilitated diffusion require a plasma membrane?

A

Facilitated diffusion

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

What substances are directly/indirectly related to the simple diffusion rate?

A

Directly: temperature, gradient, surface area
Indirectly: resistance (viscocity of fluid; size of molecule), diffusion distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What substances are directly related to the facilitated diffusion rate (FDR) of ions?
Gradient, temperature, # of channels, probability the channels are open
26
What substances are directly related to the facilitated diffusion rate (FDR) of hydrophilic building blocks?
Gradient, temperature, # of carriers, probability the channels are active
27
What is simple diffusion regulated by?
Changing concentration gradient
28
What is facilitated diffusion regulated by?
Changing resistance
29
Why are the kinetics different?
Facilitated diffusion has saturation due to membrane carriers Simple diffusion moves directly though a bilayer so there is nothing to saturate
30
1. Which way will dots move via diffusion? 2. Which way will triangles move via diffusion? 3. What type of substance could the triangles represent? 4. If the stars represent a hydrophobic substance, what would increase the diffusion rate of stars?
1. Net movement into cell 2. No net movement because the membrane isn't permeable to the triangles 3. triangle is impermeable to membrane so must represent hydrophilic substance (glucose, potassium, etc) 4. ↑ΔC, ↑SA, ↑T, ↓R, ↓D
31
What is another type of passive transport?
Osmosis
32
What is osmosis?
Movement of H2O across a plasma membrane down a [free H2O] gradient
33
Water movement via osmosis is facilitated by?
Aquaporins
34
Can water permeability be regulated?
Yes
35
What is free water inversely related to?
Solute concentration
36
How do water molecules move down a free water gradient?
Passively (toward the area with a higher solute concentration)
37
Which direction do we have water movement between the tanks?
From tank 2 to tank 1
38
What values are dependent on osmosis to occur?
1. Solute concentration 2. Water concentration 3. Container volume
39
Which direction will there be net movement of H2O? *membrane permeable to H2O only *dots and stars are not permeable
No net water movement, it is not substance specific
40
Which direction will there be net movement of H2O? *membrane is permeable to water and stars NOT dots
Tank 2 to tank 1 - you could ignore the substances permeable to the membrane (stars) - take home: only the impermeable substances influence the movement via osmosis
41
Which way will water move via osmosis?
Out of the cell - since the membrane is permeable to water, dots, stars, and squares, they can be ignored. From there, the things move out the cell because the solute concentration is higher outside the cell so thats where water will go
42
What is osmolarity?
The total (free) solute concentration of a solution (permeable and impermeable solute)
43
What is 1 osmol equal to?
1 mol of solute particles So a 1 M solution of glucose has a concentration of 1 Osm (1 osmol per liter), whereas 1 M solution of sodium chloride is 2 Osm (2 osmol of solute per liter of solution) NaCl (1) -> Na+(1) + Cl-(1)
44
Cells bathing solution is defined by its Osm:
1. Isosmotic 2. Hyposomotic 3. Hyperosmotic
45
What is isosmotic?
Bathing solution Osm = cytosolic Osm
46
What is hyposmotic?
Bathing solution Osm < cytosolic Osm
47
What is hyperosmotic?
Bathing solution Osm > cytosolic Osm
48
What is tonicity defined by?
Impermeable substances only
49
What does tonicity determine?
The direction of H2O movement via osmosis
50
Cell's bathing solution can be defined by its tonicity:
1. Isotonic solution 2. Hypotonic solution 3. Hypertonic solution
51
What is an isotonic solution?
1. Concentration of impermeable solute = cell cytosol 2. Cells in an isotonic bathing solution will have no net volume
52
What is a hypotonic solution?
1. Concentration of impermeable solute < cell cytosol 2. Cells in a hypotonic bathing solution will gain water and swell
53
What is a hypertonic solution?
1. Concentration of impermeable solute > cell cytosol 2. Cells in a hypertonic bathing solution will lose water and shrink
54
What is the osmolarity and tonicity of the bathing solution?
Hyposomotic Hypotonic
55
Which direction will water flow via osmosis?
Right
56
What are permeable solutes?
Ethanol Fatty acids O2 CO2 Steroids Urea - passive transporters Glucose (dextrose) - actions of insulin dependent on diabetes can move to impermeable category
57
What are impermeable solutes?
Na K Cl HCO3 Protein
58
What does permeability depend on?
Cell type (ex: RBC always permeable to urea and glucose) Chemical signals present at the time (ex: liver and muscle cells only permeable to glucose if insulin present)
59
If asking about a single cell AND identity not provided, what can we assume regarding permeability regarding glucose and urea?
Glucose and urea may be impermeable
60
If asking about the body over time, what can we assume regarding permeability regarding glucose and urea?
Glucose and urea are permeable
61
Define the osmolarity, tonicity, and direction of water movement
Hyperosmotic - 400 outside, 300 inside isotonic - NaCl is the only thing impermeable - 300 outside, 300 inside No volume change - cells in an isotonic solution don't have a change in volume
62
Define the osmolarity, tonicity, and direction of water movement
Hyperosmotic - 400 outside, 200 inside Hypertonic - 400 outside, 200 inside Water moves out of the cell due to higher concentration outside the cell
63
Define the osmolarity, tonicity, and direction of water movement
Isoosmotic - 300 outside, 300 inside Hypotonic - 100 outside, 300 inside Water moves into the cell due to a higher concentration inside the cell
64
What happens when a RBC is placed in a hypertonic, isotonic, and hypotonic solution?
Hypertonic: shriveled cell Isotonic: normal Hypotonic: cells swell and eventually burst
65
A
Osmolarity: Hyperosmotic Tonicity: Isotonic Volume: No change in cell volume
66
B
Osmolarity: Isoosmotic Tonicity: Hypotonic Volume: Flow into cell, increase volume
67
C
Osmolarity: Hyperosmotic Tonicity: Hypertonic Volume: Cells decrease volume and shrink

D1 Spring - Physiology (17 decks)

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