Neurons, Sodium-Potassium Pump, Uniport & Cotransport

Question 1

the sodium potassium pump is an example of the active transport mechanism. This system is utilized in every animal cell to transport … and …, maintaining a relatively high concentration of …. and relatively low concentration of …. inside the cell.

Answer 1

Na+; K+; potassium; sodium

Question 2

(sodium potassium pump) the pump binds … and then binds … intracellular … ions

Answer 2

ATP; 3; Na+

Question 3

(sodium potassium pump) ATP is …, leading to … of the pump and subsequent release of …

Answer 3

hydrolyzed; phosphorylation; ADP

Question 4

(sodium potassium pump) A … change in the pump exposes the Na+ ions to the …. The phosphorylated form of the pump has a low affinity for … ions, so they ….

Answer 4

conformational; outside; Na+; are released

Question 5

(sodium potassium pump) The pump binds … extracellular … ions. This causes the … of the pump, reverting it to its previous … state, transporting the … ions into the cell.

Answer 5

2; K+; dephosphorylation; conformational; K+

Question 6

(sodium potassium pump) The unphosphorylated form of the pump has a higher affinity for Na+ ions than K+ ions, so the two bound K+ ions are …. …. binds and the process …

Answer 6

released; ATP; repeats

Question 7

neurons rely on the unequal distribution of … and … ions to …. (known as …) throughout the nervous system

Answer 7

sodium; potassium; transmit signals; action potentials

Question 8

in a resting neuron (one not sending signals), the ionic gradient produced by the sodium-potassium pump generates a resting potential of … to … mV

Answer 8

-60; -80

Question 9

a certain amount of sodium and potassium is always leaking across the membrane through leakage channels, but sodium potassium pumps in the membrane actively

Answer 9

restore the ions to the appropriate side

Question 10

nerve impulses are passed along neurons by a … of the membrane. an action potential is triggered when the membrane potential increases to between …. and … mV

Answer 10

depolarization; -40;-55

Question 11

when this … value is reached, … gates open causing these ions to move … the cell

Answer 11

threshold; sodium; into

Question 12

the influx of Na+ triggers … to open, releasing … ions … the cell. This depolarization of the cell signals the next neuron in the pathway to …

Answer 12

K+ gated channels; potassium; from (outside of); depolarize

Question 13

the neuron returns to its original state through the action of …. embedded in the membrane and the original concentration gradients are …

Answer 13

sodium/potassium pumps; reestablished

Question 14

Uniport: when …. type of molecule moves in a … through the cell membrane, independent of other molecules

Answer 14

one; single direction

Question 15

Symport (co-transporter): … kinds of molecules move in … direction at the same … through the cell membrane

Answer 15

two; the same; time;

Question 16

Antiport (exchanger): … kinds of molecules move in the … direction through the cell membrane –> binding on … sides of the transport protein

Answer 16

two; opposite; opposite

Question 17

antiport and symport can be … (but not always)

Answer 17

active transport

Question 18

facilitated diffusion is

Answer 18

uniport

Question 19

symport and antiport powered by the … of ….

Answer 19

breakdown; ATP

Question 20

cotransport incorporates the movement of one type of ion or molecule …. its concentration gradient and one type of ion/molecule … its concentration gradient –> both … and …. transport

Answer 20

against; down; passive; active

Question 21

sodium potassium pumps are an example of … due to the fact that they are moving in … directions across the membrane

Answer 21

antiport; opposite

Question 22

ATP synthase is an enzyme complex in the membrane that contains a channel, making it both a … and an … protein

Answer 22

channel; enzymatic

Question 23

As a channel, ATP synthase allows … to flow down its … gradient - a gradient based on the …. differences and …. across the cell membrane

Answer 23

H+; electrochemical; electrical potential; chemical concentrations

Question 24

The movement of H+ into the cell provides the necessary … that allows for the production of ….

Answer 24

kinetic energy; ATP

Question 25

ATP synthase transport is ... in that only one type of substance, the ...., are being transported through the channel, all moving in the ... direction

Answer 25

uniport; hydrogen ions; same

Question 26

Action potential defines a change in ... across the ... and consists of three stages: ..., ..., and ...

Answer 26

polarity; axonal membrane; depolarization; repolarization; hyperpolarization

Question 27

beginning with a resting membrane potential of -70 mV, a sufficiently large ... is applied such that the threshold-- the minimum change in ... necessary for an action potential to occur-- is reached and the ... is initiated

Answer 27

stimulus; polarity; action potential

Question 28

the first stage of an action potential is ..., in which the intra-axonal portion of the membrane becomes ...

Answer 28

depolarization; positive

Question 29

Depolarization occurs because, when the threshold is reached, many ... open, and there is an influx of ... into the axon, causing the voltage to increase from ... mV to ... mV

Answer 29

sodium channels; sodium ions; -70; +40

Question 30

the significant increase in voltage prompts ... to open, while ... close

Answer 30

potassium channels; sodium channels

Question 31

potassium ions then leave the axon in a stage known as ...., causing the voltage of the axon to return back to the ... of ... mV

Answer 31

repolarization; resting membrane potential; -70

Question 32

however, the voltage continues to decrease, causing ..., as the gated potassium channels are ...

Answer 32

hyperpolarization; leaky

Question 33

the axon again returns to -70 mV, due to the ... that continually pump ... ions out of the cell and .... ions into the cell

Answer 33

sodium/potassium pumps; 3 sodium; 2 potassium

Question 34

dendrites: receive ... (...)

Answer 34

signals; neurotransmitters

Question 35

nerves ... make contact with other nerves/muscles

Answer 35

do not

Question 36

neurotransmitter: made up of ..., suggests that dendrite must have ... on the surface

Answer 36

proteins; protein receptors

Question 37

node of

Answer 37

ranvier

Question 38

openings of myelin sheath (...) coating the ... --> fat because it is ... and is ...

Answer 38

fat; axon; insulating; slipper

Question 39

myelin sheath helps to speed up

Answer 39

conduction

Question 40

without myelin sheath, the signal is ...., not going in same ...

Answer 40

dispersed; line

Question 41

action potential (...) always progresses in .... direction due to the ... in previous node

Answer 41

saltatory conduction; a single; hyperpolarization

Question 42

synapse: space between ... and between ... and ...

Answer 42

nerves; nerves; muscles

Question 43

examples of neurotransmitters: ..., ..., ... (ACL)

Answer 43

dopamine; serotonin; acetylcholine

Question 44

tetanus - ..., leads to ... --> muscles locked in ..., leads to inability to ..., trouble ..., interrupting ..., ...

Answer 44

bacteria; lock jaw; contraction; swallow; breathing; speech; death

Question 45

tetanus progresses as ..., ... not broken down in this case

Answer 45

bacteria divide; acetylcholine

Question 46

node contains: ... pump, ...

Answer 46

sodium/potassium pump; voltage gated sodium & potassium channels

Question 47

action potential jumps from ... to ..., but adjacent ones are never doing the same thing at the same time --> ...

Answer 47

node; node; saltatory conduction

Question 48

ion channels: proteins extending across the cell membrane, allowing for the passage of ... into or out of the cell

Answer 48

ions

Question 49

ion channels are specific to certain ions and are opened for a short amount of time in response to ..., meaning that they are ...

Answer 49

signals; gated

Question 50

the transport of ions across ion channels is a form of ... transport, as no ... is required

Answer 50

passive; energy

Question 51

two predominant groups of transport proteins:

Answer 51

channel & carrier proteins

Question 52

both channel and carrier proteins create a passageway for molecules to enter/exit a cell, but carrier proteins .... when moving substances across the membrane

Answer 52

change their shape

Question 53

ATP pumps are proteins that engage in the active transport of substances ... their concentration gradients, powered by the ... of ... into ... and ...

Answer 53

against; hydrolysis; ATP; ADP; phosphate

Question 54

Another example of active transport using an ATP pump is the ... exchanger in the stomach

Answer 54

hydrogen/potassium

Question 55

for the hydrogen/potassium exchanger, hydrogen ions are transported from a region of ... concentration to a region of ... concentration to make gastric juices especially acidic

Answer 55

low; high

Question 56

with multiple sclerosis, myethin sheaths are damaged which impedes .... between different regions of the brain. This leads to various stages of ..., .... problems, and general ...

Answer 56

transmission of signals; paralysis; vision; weakness