Brainscape's Knowledge GenomeTM

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


See full index

Neuro 3000 > Neuronal Membrane at Rest > Flashcards

Neuronal Membrane at Rest Flashcards

1
Q

What is the equilibrium potential for Na+?

A

62 mV

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

Key channels in determining a neurons resting membrane potential (Vm)

A

K channels

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

Conducts signal without loss of strength; required to send fast signals down long axons (charge replenished all the way down)

A

AP

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

What must the plasma membrane have to generate a rest pot?

A

High resistance when channels are closed, can act as a capacitor

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

What controls the movement of ions in cells?

A

Diffusion and electrical forces

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

Made up of 4 separate proteins that form the pore

A

K channels

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

Secondary protein structure

A

Alpha helices and beta pleated sheets

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

What must membrane proteins have to generate a rest pot?

A

Specific proteins localized to soma, dendrites, axon (specific proteins at specific locations)

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

How much current flows depends on these two things

A
  1. Electric potential (voltage V)

2. electrical conductance

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

What is the equilibrium potential for Ca2+?

A

123 mV

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

The potential difference that balances the ionic concentration gradient for any given ion (the voltage that balances diffusion)

A

Ionic equilibrium potential

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

Changing the concentration of this outside can cause the cell to depolarize, application seen in lethal injections

A

K

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

What do excitable cells have at rest?

A

A resting membrane potential which is negative (inside compared to out)

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

What three things are involved in generating a resting potential?

A

Cytosol and extracellular fluid, plasma membrane, and membrane proteins

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

How does a cell develop a rest pot?

A

Controlling what ions can move across the membrane

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

Something that stores charge

A

Capacitor

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

4 protein structures

A

primary, secondary, tertiary, and quaternary

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

How does rest. pot. vary between neurons? What does -65 represent?

A

Different types have different rest pots and -65 is the average

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

Forms barrier to water and ions and allows membrane potentials to form

A

Phospholipid bilayer

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

What produces large changes in membrane potential?

A

Tiny changes in ionic concentrations ( ~.00001 M)

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

Ions are surrounded by clouds of water called this in the cytosol and extracellular fluid

A

Spheres of hydration

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

A measure of the difference in charge between anode and cathode (force on particle), more difference = more current

A

Voltage

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

What do ions move across the membrane at a rate proportional to?

A

Ions move across the membrane at a rate proportional to the difference between the membrane potential and the equilibrium potential for an ion (driving force)

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

What is the protein structure of many channels?

A

Quaternary

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

Uses ATP for energy to exchange internal Na+ for external K+

A

Na/K pump

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

Occurs when diffusional and electrical forces are equal and opposite (they are in balance) (voltage that balances diffusion)

A

Equilibrium state

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

Made up of 1 protein that folds up to look like 4 to form the pore

A

Na channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Equation to calculate the exact equilibrium potential for an ion

A

Nernst equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Mutations to these lead to severe neurological problems or death (channelopothies)

A

K channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What must the cytosol and extracellular fluid have to generate a rest pot?

A

Each needs a specific ion concentration and composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the properties of every cell determined by?

A

Types of proteins expressed in membranes and cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

These are produced by the movement of ions, which follow the basic electrical principles

A

APs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Transports Ca2+ out of the cell, other proteins and channels help as well

A

Ca2+ pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The cells can generate APs like nerve impulses and spikes (neurons and cardiac cells)

A

Excitable cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the equilibrium potential for Cl-?

A

-65 mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Voltage across the membrane

A

Membrane potential (Vm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Calculates membrane potential of a cell at any given time (Vm)

A

Goldman equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Work against concentration gradient to maintain concentration difference

A

Ion pumps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

The Goldman equation accounts for this whereas the Nernst equation doesnt

A

Relative permeability to multiple ions

40
Q

Each ion has its own one of these

A

Ionic equilibrium potential

41
Q

What is the equilibrium potential for an ion inversely related to ?

A

Charge

42
Q

These are the major charge carrier in the cytosol/extracellular fluid

A

Ions

43
Q

To conduct an AP, what must a cell have?

A

A resting potential

44
Q

Tertiary protein structure

A

Folding into subunit (many stop here)

45
Q

Is the relative ability for a charge to move from one place to another, depends on number of particles available to carry the charge and how easily these can travel (is the channel open/how open)

A

Conductance (g, Siemens)

46
Q

How much more K+ is inside than outside?

A

20x more inside

47
Q

This conduction of a signal only works for short distances; for the most part cant send signals quickly (current carried by short range diffusion)

A

Passive conduction

48
Q

First cloned in fruit fly, but not the one that sets the resting potential

A

K channels

49
Q

Concentrations of K+, Na+, and Cl- inside/outside

A 
K = higher in
Na = higher out
Cl = higher out
50
Q

Where do the net differences in charge occur?

A

At the inside and outside surfaces of the membrane (5nm thick)

51
Q

What can changing K concentration outside the cell cause?

A

Change in membrane potential

52
Q

I (electrical current) = g (conductance) * V (voltage)

A

Ohm’s law

53
Q

How is the equilibrium potential for K+ made?

A

Diffusion wants K+ to leave and electrical forces want it to stay in

54
Q

What is the neuron resting potential

A

-65 mV

55
Q

These two determine whether the inside of a cell is positive or negative at equilibrium for each ion

A

Charge and concentration difference

56
Q

What is the equilibrium potential for K+?

A

-80 mV

57
Q

What determines the properties of the 20 amino acids?

A

R groups

58
Q

Ions important for neurophysiology

A

Ca2+, K+ (only one higher inside), Na+, and Cl-

59
Q

This channel being cloned in fruit flies lead to isolation of many other of these channels and understanding of many channel structures

A

K channels

60
Q

Each ion has a different one of these calculated from the concentration difference across the membrane

A

Equilibrium potential

61
Q

How does K spatial buffering occur and what is it?

A

Astrocytes pick up K and distribute it around to not let one area get too high in concentration

62
Q

What happens when V=0?

A

No current flows even if channels are open

63
Q

What is the membrane potential close to and why?

A

Close to equilibrium potential for K (Ek) due to high permeability of cell to K

64
Q

Involved in the blood brain barrier (muscle not protected)

A

External K concentration

65
Q

Knowing 2 of these 3 can be used to determine the other

A

Charge, higher concentration inside or outside, and equilibrium potential of the ion

66
Q

These are important for how ions move through channels

A

Spheres of hydration

67
Q

How does myelination help create a net difference in charge and get rid of the membrane capacitor problem?

A

Myelination separates + and - charges from each other for faster signaling (faster APs)

68
Q

Chains of amino acids are called this and held together buy these

A

Polypeptide, peptide bonds

69
Q

What are proteins made of?

A

One or more polypeptides

70
Q

Used manipulation of the external K concentration to show that resting potential is mostly set by K permeability of neuron

A

Hodgkin and Katz

71
Q

The relative inability of an electric charge to migrate (inverse of conductance)

A

Resistance (R, ohms)

72
Q

Have both hydrophobic and hydrophilic regions, are selective, and can be controlled

A

Ion channels

73
Q

What happens when g=0?

A

No current flows even if a voltage difference

74
Q

What is the equilibrium potential for K+?

A

-80 mV

75
Q

What would happen without the negative potential inside a neuron?

A

No transmission

76
Q

These modulate K levels

A

Astrocytes

77
Q

What is an example of a K channel mutation

A

Losing selectivity to K and allowing Na in and the resting potential is raised

78
Q

What do simple reflex actions require?

A

Rapid signaling and integration of info

79
Q

The inside of the cell is more this than the outside

A

Negative

80
Q

Vm (membrane potential) - Eion (equilibrium potential for an ion)

A

Driving force

81
Q

Major component of cytosol and extracellular fluid

A

Water

82
Q

What does the membrane act like in generating net differences in charge? Why is this a bad thing?

A

It acts as a capacitor (stores charge) and it is not a good thing because it inhibits fast electrical signaling

83
Q

Movement of charge, positive in the direction of positive charge movement

A

Electrical current (I)

84
Q

How does an AP occur?

A

A brief reversal of charge, not reversal of gradient

85
Q

This forms a high resistance barrier to ion until ion channels are opened

A

Lipid bilayer

86
Q

Quaternary protein structure

A

Joining of multiple subunits into 1

87
Q

Positioning of phospholipids in bilayer

A

Hydrophilic heads toward water (outside) and hydrophobic tails towards inside of membrane

88
Q

Primary protein structure

A

Chain of amino acids

89
Q

What voltage does an AP peak at?

A

30 mV

90
Q

How do ions move into a cell in terms of direction?

A

Move in direction that moves the cell towards the equilibrium potential for that ion

91
Q

Uses 70% of brain ATP, active transport, and electrical trial signaling won’t work without it

A

Na/K pump

92
Q

Transport ions across membranes against concentration gradients using ATP as the energy source

A

Pumps

93
Q

What generates the average resting potential of a neuron?

A

Constant leak of K+ from the cell through leak channels (K+ is constantly diffusing out causing a - charge inside)

94
Q

What do ions need to be able to move by diffusion?

A

Channels

95
Q

Random movement from region of high concentration to low concentration, temp dependent (faster when warmer), must have a path through the lipid bilayer (like a channel)

A

Diffusion

Neuro 3000 (15 decks)

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