Chapter 12: Membrane Transport

Question 1

What kind of molecules diffuse the easier across the lipid bilayer?

Answer 1

small non polar molecules

Question 2

What kind of molecules are the second easiest to diffuse across the lipid bilayer?

Answer 2

small uncharged polar molecules

Question 3

What kind of molecules are the third easiest to diffuse across the lipid bilayer?

Answer 3

larger uncharged polar molecules

Question 4

What kind of molecules can’t diffuse across the lipid bilayer?

Answer 4

ions

Question 5

Concentration of Na+ inside the cell

Answer 5

5-15

Question 6

Concentration of Na+ outside of the cell

Answer 6

145

Question 7

Concentration of K+ inside of he cell

Answer 7

140

Question 8

Concentration of K+ outside the cell

Answer 8

5

Question 9

Concentration of Ca2+ inside the cell

Answer 9

10^-4

Question 10

Concentration of Ca2+ outside the cell

Answer 10

1-2

Question 11

Concentration of Cl- inside the cell

Answer 11

5-15

Question 12

Concentration of Cl- outside the cell

Answer 12

110

Question 13

Down Hill Movement

Answer 13

movement from high to low concentration

Question 14

Gibbs free energy equation

Answer 14

inside concentration over outside solute

Question 15

Carriers/Transporters

Answer 15

Facilitated passive diffusion can be active

Question 16

Channels

Answer 16

passive only

Question 17

Membrane Potential

Answer 17

voltage across the membrane that exerts a force on charged molecules

Question 18

electrochemical gradient

Answer 18

sum of the concentration and electrical forces

Question 19

2 components to electrochemical gradient

Answer 19

internal and external potential

Question 20

Animal cells charge along the inner membrane

Answer 20

negative charge

Question 21

membrane potential of animal cells

Answer 21

• 60 mV

Question 22

Transport of solutes against their electrochemical gradient

Answer 22

uphill transport

Question 23

3 types of Active Transport Pumps

Answer 23

coupled transporter, ATP- driven pump, light driven pump

Question 24

ATP drive pumps

Answer 24

sodium potassium pump; pumps sodium out and potassium in against their electrochemical gradients

Question 25

How much of he total ATP produced goes to sodium potassium pump?

Answer 25

30%

Question 26

of molecules transferred in sodium potassium pump

Answer 26

3 sodium 2 potassium

Question 27

Coupled transporters

Answer 27

symport and anti porter are coupled as something comes in something goes out

Question 28

dendrites

Answer 28

branch off of the cell body which receives signals

Question 29

terminal branches of axon

Answer 29

signal transmitting side

Question 30

axon

Answer 30

transports the signal from the cell body to the terminal branches

Question 31

How is the signal communicated

Answer 31

a change in membrane potential

Question 32

4 types of ion channels

Answer 32

1) voltage gates
2) ligand gated (extracellular)
3) ligand gated (intracellular)
4) stress gated

Question 33

What is the cause of migraines ?

Answer 33

voltage activated/gated Ca2+ channel

Question 34

What is the cause of myasthenia graves

Answer 34

acetylcholine receptor Na+ channel

Question 35

What causes cystic Fibrosis

Answer 35

Cl- transporter; perturbed H2O balance increases susceptibility to bacterial infections

Question 36

What do potassium leak channels allow?

Answer 36

potassium to move down its chemical gradient( out of the cell) leaving back. net negative charge

Question 37

what is the role of potassium leak channels ?

Answer 37

set the membrane potential

Question 38

What happens when a localized membrane depolarization is large enough to pass a critical threshold

Answer 38

it will activate college gated Na+ channels further depolarizing the membrane ( action potential)

Question 39

What is the value when the membrane is fully depolarized?

Answer 39

+40 mV

Question 40

What happens when a membrane is fully depolarized?

Answer 40

voltage gated sodium channels adopt an inactivated conformation

Question 41

How is the membrane depolarized?

Answer 41

1) voltage gated sodium channels are inactivated
2) voltage gated potassium channels are activated
3) potassium leak channels continue to función

Question 42

What direction does a action potential spread?

Answer 42

unidirectionally

Question 43

What do myelin sheath do ?

Answer 43

allows faster propagation of an action potential

Question 44

Multiple Sclerosis

Answer 44

autoimmune disorder resulting in the gradual destruction of the myelin sheath

Question 45

Synaptic Cleft

Answer 45

target cells are separated from the nerve terminal by a 20 nm gap

Question 46

Can action potential cross synapse?

Answer 46

no it is converted to neurotransmitters

Question 47

What happens once the action potential is converted to neurotransmitters?

Answer 47

Ca2+ channel is activated which triggers the fusion of synaptic vesicles with the plasma membrane releasing the stored neurotransmitters into the synaptic cleft

Question 48

What’s the last step before a new action potential is created?

Answer 48

neurotransmitters bind to receptors ( ligand gated ion channels) on the target cell ( postsynaptic cell)

Question 49

Excitatory neurotransmitters ( initiate an action potential)

Answer 49

Acetylcholine
Glutamate(Na+ channels)

Question 50

Inhibitory Neurotransmitters(prevent action potential)

Answer 50

GABA
Glycine(Cl- channels) ( block depolarization)

Question 51

Neuromuscular Junction

Answer 51

Synapse between neuron and muscle

Question 52

Tranquilizers ( valium, Halcyon, temazepam)

Answer 52

Bind o GABA Cl- channels, make them easier to open cells become more sensitive to inhibition by GABA

Question 53

antidepressant (prozac)

Answer 53

blocks the re-uptake of serotonin

Question 54

What treatments target transmitters gated ion channels ?

Answer 54

insomnia, anxiety, depression, schizophrenia

Question 55

Channelrhodopsin

Answer 55

activated by blue light causes influx of sodium ions can cause mice to act crazy