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1
Q

What type of transport does the Na/K pump use? be specific. (3 words)

A

Primary active transport

2
Q

General makeup of the PM:

A

lipid and protein, 50/50

3
Q

In what tissues are PM’s electrically excitable?

A

nerve and muscle cells

4
Q

What types of signals can a PM transduce into specific cellular responses and activities?

A

electrical, chemical, and mechanical

5
Q

Molecules that can freely diffuse across PM?

A

O2, CO2, N2, benzene

6
Q

Name 3 small uncharged polar molecules that can diffuse across the PM.

A

H2O, urea, glycerol

7
Q

Rate of diffusion equation:

A

(SA X conc. gradient X PM permeability) / PM thickness

8
Q

PM permeability is proportional to:

A

lipid solubility / molecular size

9
Q

about how many AA is the transmembrane alpha-helical polypeptide segment made of?

A

20

10
Q

Do peripheral proteins create a pathway for the movement of molecules from one side of the membrane to the other?

A

No

11
Q

This is the “revolving door” type of transport protein:

A

Carrier protein

12
Q

T or F? Carrier proteins are open simultaneously to both the inside and outside of the cell.

A

F.

13
Q

Do carrier proteins use energy directly, indirectly, or both?

A

both

14
Q

Can carrier proteins move molecules against their concentration gradient?

A

Yes

15
Q

T or F? Channel proteins selectively allows for specific molecules to be transported across the membrane.

A

F. It has no control over what diffuses or the rate of difusion

16
Q

From where is energy derived in secondary transport?

A

the potential energy of the concentration gradient of a molecule (used to move another molecule against gradient)

17
Q

What molecule is frequently used in secondary transport to create the concentration gradient from which the energy is derived to transport the other molecule in secondary active transport?

A

Na

18
Q

Is there typically a higher concentration of Na inside or outside the cell?

A

Outside

19
Q

T or F? 2 Na are pumped out for every 3 K that are pumped in.

A

F. 3 Na out/ 2 K in

20
Q

Does the Na/K pump make the inside of the cell more or less positive with every pump?

A

less positive

21
Q

How many transmembrane segments does the large alhpa subunit the Na-K pump have?

A

10

22
Q

Which subunit positions the Na-K pump in the membrane?

A

extracellular beta subunit

23
Q

How many times does the gamma subunit of the Na-K pump cross the membrane?

A

1 time

24
Q

How many subunits does the Na-K pump have and name them.

A

3, alpha, beta, gamma

25
Q

What is required for the transitional changed bw open and closed states of the Na-K pump?

A

ATPase activity, P binds to the protein carrier

26
Q

What charge does P have?

A

-

27
Q

What should you add to a protein if you want to change its shape?

A

P

28
Q

How is the conformation of the Na-K pump changed once the Na has been released to the ECF and K has bound?

A

P is removed, causing the change in shape

29
Q

How many ATP are required for each cycle of opening and closing of the Na-K pump?

A

1 ATP

30
Q

What percentage of the energy of the body is consumed by the Na-K pump?

A

about 25%

31
Q

What percentage of the energy of the brain is consumed by the Na-K pump?

A

about 70%

32
Q

T or F? The more Na outside the cell, the lower the stored PE

A

F. greater PE

33
Q

Creates a charge gradient:

A

electrogenic

34
Q

Does the Na-K contribute a large amount to the resting negative MP of neurons?

A

No

35
Q

Does the Na-K contribute a large amount to the resting negative MP of smooth muscles?

A

Yes

36
Q

T or F? The Na-K contributes more to the resting negative MP of the neuron than of smooth muscle.

A

F. contributes more to the smooth muscle

37
Q

The transport of Na into the cell is often coupled with the transport of this into the cell:

A

glucose

38
Q

What is the name of the protein carrier involved in the coupled transport of Na and glucose into the cell?

A

SGLT protein

39
Q

The binding of what molecule causes the change in conformation of the SGLT protein?

A

glucose

40
Q

Which molecule is both the first to bind on the EC side and release on the IC side of the SGLT protein?

A

Na+

41
Q

What other pump/exchanger depends on the Na-K pump?

A

Na-Ca exchanger

42
Q

How would the Ca concentration be effected, if at all, if the Na-K pump was non-functional while the Na-Ca exchanger was functional?

A

Ca++ will build up in the cell

43
Q

What effect will digitalis have on a cell?

A

it will raise the Ca++ levels in the cell

44
Q

What effect will digitalis have on the heart?

A

enhance muscle contraction, improving muscle function

45
Q

What type of transport does the Na-Ca use?

A

Secondary Active Transport

46
Q

What effect does ouabain have on a cell?

A

blocks the Na-K pump

47
Q

What 2 drugs can block the Na-K pump?

A

ouabain and digitalis

48
Q

What effect will low doses of digitalis have on the heart muscle?

A

raise Na inside heart muscle

49
Q

How will the Ca levels in the heart muscle be effect with low doses of digitalis?

A

Na levels will be raised and this will slow the removal of Ca via the Na-Ca exchanger

50
Q

Another name for potential difference:

A

voltage

51
Q

T or F? The Na/K pump creates a lare negative charge inside the cell.

A

F. Only creates a small neg charge in cell

52
Q

You should always assume he net charge outside the cell is:

A

zero

53
Q

When is the resting MP the EP (equilibrium potential)?

A

electrical gradient exactly opposes the chemical gradient

54
Q

Around how much K would have to leave the typical cell to reach EP (equilibrium potential)?

A

very little, less than 1/10th

55
Q

Functions of electrical signals in neurons:

A
  1. combine info from many inputs
  2. transmit info
  3. activate mem proteins
  4. stimulate transmitter release
56
Q

Mathematic term for membrane potential difference:

A

Vm

57
Q

70 mV = 70 ____ th of a volt:

A

thousandth

58
Q

in what type of solution is a cell placed when measuring internal voltage with a voltmeter?

A

saline solution

59
Q

How can you measure a current?

A

count the # of ions passing through (ions/sec)

60
Q

This is the energy to move charge:

A

voltage

61
Q

How is conductance calculated?

A

1/Resistance

62
Q

This is a measure of the ease of moving a charge across a membrane:

A

conductance

63
Q

2 ways to decrease conductance:

A

make path longer or more narrow

64
Q

T or F? Excitation is occurring when a cell is made more positive.

A

T

65
Q

T or F? Excitation is occurring when a cell is made more negative.

A

F. inhibition

66
Q

T or F? Excitation of the cell leads to polarization of the cell.

A

F. Depolarization

67
Q

T or F? The flow of Cl- into a cell will lead to depolarization.

A

F. hyperpolarization

68
Q

Will the outflow of K+ from a cell depolarize of hyper polarize the cell?

A

hyperpolarize

69
Q

2 ways to hyperpolarize a cell:

A

Increase flow of Cl- in or increase flow of K+ out

70
Q

Depolarization initiates what 2 events?

A

AP production and neurotransmitter release at synapse

71
Q

Would hyperpolarization make the production of an AP more or less difficult?

A

more

72
Q

T or F? When the cell depolarizes the membrane potential increases.

A

F. The membrane potential decreases.

73
Q

T or F? When the cell hyperpolarizes the membrane potential increases.

A

T

74
Q

What do aquaporin channels allow the passage of?

A

water, glycerol, ammonia, and urea

75
Q

Can charge molecules pass through aquaporins?

A

No

76
Q

How many times does the aquaporin span the membrane?

A

6-transmembrane structure

77
Q

Where are aquaporins most prominent?

A

kidney

78
Q

T or F? Facilitated diffusion can move molecules across a membrane that would normally not cross the membrane over any amount of time, no matter how long.

A

F. Any of the molecules would pass through, some just very slowly

79
Q

is the carboxylic end of the aquaporin positioned on the L or R side?

A

R

80
Q

T or F? As the solute concentration of a fixed volume of water increases, the concentration of the water increases.

A

F. the concentration of the water decreases

81
Q

Will the concentration of water increase of decrease when salt is added to 1L of water?

A

decrease

82
Q

symbol for osmotic pressure:

A

symbol for pi

83
Q

define osmotic pressure:

A

hydrostatic pressure (force) required to counterbalance osmosis

84
Q

Which solution has a higher water concentration, 0.1 M sucrose solution or 0.01 M sucrose solution?

A

0.01 M sucrose solution

85
Q

This is the pressure water exerts on a membrane dividing two compartments filled with solution:

A

osmotic pressure

86
Q

Equation for osmolarity:

A

molarity of solute X # of solute particles that dissociate in solution

87
Q

What is the osmolarity of 0.15 M NaCl?

A

0.3 osm

88
Q

What is the osmolarity of 0.1 M MgCl2?

A

O.3 osm

89
Q

What is the osmolarity of body fluids, e.g. CSF?

A

.35 osm

90
Q

if the cell’s volume increases when placed in a solution, the solution is (hyper/hypo)tonic?

A

hypo

91
Q

if the cell’s volume decreases when placed in a solution, the solution is (hyper/hypo)tonic?

A

hyper

92
Q

whether water would go in or out of a cell when placed in solution:

A

tonicity

93
Q

Molarity of blood:

A

0.15 M (check)

94
Q

What can happen to neurons when they are under stress such as in a stroke?

A

they can lyse

95
Q

T or F? All isosmotic solutions are isotonic solutions.

A

F

96
Q

What would happen to a RBC placed in a 0.3M glycerol solution?

A

it will lyse

97
Q

How can a cell avoid lysing if it is place in a hypotonic solution?

A

swell channels, allowing solute to leave the cell

98
Q

What molecule(s) can leave the cell via swell channels?

A

Cl- (and K+?)