Question

what would happen with the Vrest if Sodium–Potassium Exchange Pump were broken？

Answer 1

u mean resting potential ?

Answer 2

yes

Answer 3

@Abhisar

Answer 4

Ohkay..u knw what resting potential is ?

Answer 5

I want you to reply fast man !!!

Answer 6

你明白静息电位？

Answer 7

快速回复

Answer 8

钾泵钠的功能是维持静息膜电位。因为（3娜）泵出，每2 k移动有钠高了很多梯度比英寸以外因此，如果此操作可关闭娜将在移动，比K快将迁出，细胞会去极化。

Answer 9

so if the Sodium–Potassium Exchange Pump were inaction， the cell' rest potential will increase?
@Abhisar btw please just type the answer in English, because yr Chinese translation isn't correct.

Answer 10

:D i knw .. u were not responding at english so i thought it would be better to reply in chinese...also it looks like u used google translator to post ur question which in addition forced me to believe u dont understand english

Answer 11

so am i right?

Answer 12

@alphadxg

Answer 13

thx :D

Answer 14

Anytime !

Answer 15

But do cross check !

Answer 16

@Somy

Answer 17

O oh, the answer in my textbook is The activity of the sodium-potassium pump is essential to maintain the resting potential. With the pump inactivated, the sodium and potassium concentration gradients would gradually disappear, resulting in a greatly reduced resting potential.

but i think if the sodium and potassium concentration gradients disappear, the rest potential must trend to zero, the rest potential increase! @Abhisar

Answer 18

ohkay now wait....i'll hv to take out my physiology book..i studied them long time back

Answer 19

are you guys talking about cell surface membrane? @Abhisar

Answer 20

see the negative sign of the resting potential (-70mV) shows that inside the cell is negative whle outside the cell is positive

Answer 21

@Somy yes, like axolemma

Answer 22

resting potential means the potential difference across the membrane

Answer 23

im not really sure whats the answer but logically thinking if we look at membrane and at sodium potassium pump
the basic function of Na and K is to maintain the charges in the cell thus the gradient. If this pump is inactive that means the gradient of charges will either increase or decrease. So this maintained gradient would be destroyed. Since Na is actually needed to pump out and K is needed to constantly come in or the opposite way round then that means some functions will basically stop, example Glucose that used to come in along with Na cannot come like that anymore
now then no exchange happens, cell is alive so its continuously active, thus obviously K and Na that are in the cell will be used up in some functions right? so thats why the gradient will drop in the cell

Answer 24

im not sure if its right, because im just analyzing this just by looking at the picture of the pump and knowing sever roles of this pump so i came up with this

Answer 25

the gradient will drop since number of K and Na in the cell will be less then outside the cell

Answer 26

@Abhisar i hope i didn't misunderstand the question?

Answer 27

if these pumps are active i don't think the gradient would increase rather it would just be maintained unless there is abnormalities in the pump itself

Answer 28

Yes ur ryt @Somy !
Different types of ion channels are present on the neural membrane. These ion
channels are selectively permeable to different ions. When a neuron is not
conducting any impulse, i.e., resting, the axonal membrane is
comparatively more permeable to potassium ions (K+) and nearly
impermeable to sodium ions (Na+). Similarly, the membrane is
impermeable to negatively charged proteins present in the axoplasm.
Consequently, the axoplasm inside the axon contains high concentration
of K+ and negatively charged proteins and low concentration of Na+. In
contrast, the fluid outside the axon contains a low concentration of K+, a
high concentration of Na+ and thus form a concentration gradient. These
ionic gradients across the resting membrane are maintained by the active
transport of ions by the sodium-potassium pump which transports 3
Na+ outwards for 2 K+ into the cell. As a result, the outer surface of the
axonal membrane possesses a positive charge while its inner surface
becomes negatively charged and therefore is polarised. The electrical
potential difference across the resting plasma membrane is called as the
resting potential.

Answer 29

@13xyhuang2 i hope you get it?

Answer 30

So basically there are two types of transport i.e active and passive going on simultaneously. Former tries to increase the gradient and later tries to decrease it. So it kinda maintains an equilibrium

Answer 31

hehe actually i haven't learnt about nervous system in this much details
i've just learnt the working of membrane itself so thats why i came up with this @Abhisar :D

Answer 32

Anyways...!!
Thanx a lot @Somy for taking the pain and helping us out :)

Answer 33

nah no problem i got to learn some stuff also :D @Abhisar

Answer 34

@Abhisar @Somy i know this, but what would happen with the rest potential ?

Answer 35

it will decrease

Answer 36

Yes it start fading away gradually i.e potential difference will decrease as said by @Somy

Answer 37

Don worry bou the negative sign. its just to show that cytoplasm is more negative than outside

Answer 38

@Somy you said, the gradient will drop since number of K and Na in the cell will be less than outside the cell
so the K+ Na+ will come in, but the potential will increase

Answer 39

dear this is the problem, if the pump is broken how can any of them come in?

Answer 40

@shrutipande9

Answer 41

@13xyhuang2 K and Na are charged ions and they cannot just diffuse through phospholipid bilayer
the only way for them to come in is protein channel specifically for them since its facilitated diffusion not just diffusion that happens

Answer 42

so if these K and Na channels are broken, there is no other way Na or K can come in

Answer 43

but there are still some K and Na channals active

Answer 44

did the question say that other channels are okay? if so then NO it again will not increase because now other channels will take up the work of the broken channel
and thus again maintain the gradient (tho it'll be a bit harder)

Answer 45

only Sodium–Potassium Exchange Pump inactivated

Answer 46

yes dear, that mean ALL sodium-potassium pumps are broken

Answer 47

@13xyhuang2 i think u hav not gone through ur textbooks properly !

Answer 48

It would be better if u read it carefully once again !

Answer 49

look in the membrane when it comes to protein channels then they are VERY SPECIFIC
they let ONLY sever type of ions
like in sodium potassium pump
it will let ONLY Na and K to be transported
Cl for example CANNOT pass through this K and Na channel

Answer 50

do you know how enzymes work?

Answer 51

I would like to correct one thing @Somy , Na-K pump is an active transport and not just facilitated diffusion. It requires ATP

Answer 52

yeah thats right, i just didn't mention it :D @Abhisar

Answer 53

u said this "K and Na are charged ions and they cannot just diffuse through phospholipid bilayer
the only way for them to come in is protein channel specifically for them since its facilitated diffusion not just diffusion that happens"

Answer 54

i do know. XD
but in the membrane, it have Sodium–Potassium Exchange Pump, Na+ channal, K+channal and other channals. when the Na+ k+ exchange pump inactivated, you said the concentration of K+ and Na+ inside the cell will less than outside, so because of this, K+ and Na+ will diffuse inside the cell through K+,Na+channals, the positive charges inside the cell the rest potential increase.
@Somy

Answer 55

yeah coz i was talking about diffusion :P @Abhisar

Answer 56

LOL....probably i got it wrong :D

Answer 57

thats would be right if the channel of Na and K were not broken but still the potential would not increase in any case
since the channels are BROKEN then neither facilitated diffusion nor active transport can happen so none can come in
that is why the potential will drop

Answer 58

@13xyhuang2 due see, in a Na-K pump by the use of ATP three Na+ are exported while 2 K+ are imported now this creates a potential difference as well as a conc gradient i.e Na+ conc is more outside and K+ conc is more inside.

Answer 59

Now if the pump stops the only operating process will be the diffusion (or facilitated diffusion as @Somy said :P). Now this will gradually lead to depolarisation or decrease in potential difference

Answer 60

but soon the conc gradient will disappear, i think the Na+, k+ conc will become equivalence both outside and inside the cell

Answer 61

so ??

Answer 62

BUT CELL IS LIVING so IT NEEDS Na and K
so of course the number of K and Na will decrease

Answer 63

this is what i can't figure out. π-π
btw, depolarization, the potential increase.....@Abhisar

Answer 64

i mean from negative increase to positive

Answer 65

that sign is just to indicate that inner side is more negative than outer

Answer 66

by any chance
do you not understand terms 'more negative' "less negative" ?
@13xyhuang2

Answer 67

do u think na-K pump ever stops in a normal cell?

Answer 68

i can understand this.. @Somy

Answer 69

I think what Somy is trying to say is that: Imagine everything that has to do with K is destroyed (like the channels) so that means outside the K+ will keep increasing while inside the cell is less so (more) Na will be taken in to compensate for the lack of positive charge in the Cell

However if this explanation is confusing I will delete my answer immediately ^^'

Answer 70

then i'll say it like this
the gradient inside the cell will be more negative then outside the cell

Answer 71

@Somy do u think na-K pump ever stops in a normal cell?

Answer 72

only if it disposes with some drugs.... @Abhisar

Answer 73

oh that was to me?
emm i do not think so @Abhisar
unless it is effected by a disease or genetic reasons

Answer 74

u get ur reasons then @Somy !
If it stops-----number of K and Na will decrease-----cell dies

Answer 75

@Abhisar umm reasons for what??

Answer 76

well yeah it does eventually die @Abhisar

Answer 77

the point is what happen with the rest potential...π-π

Answer 78

I feel so sorry for everyone here, right now TT_TT

Answer 79

@shreehari499

Answer 80

is d prob solved or not yet?

Answer 81

Nope

Answer 82

no since the question guy is not getting it @shrutipande9

Answer 83

ohh well then lets start from d beginning? @13xyhuang2

Answer 84

ok

Answer 85

generally cells have a higher conc of potassium and low conc of sodium inside....this is to maintain the membrane potential and to have charge separation accross the membrane..ok?

Answer 86

yep

Answer 87

generally what happens through a few pores there is generally influx of sodium inside and potassium outside by diffusion along the conc gradient..

Answer 88

then？

Answer 89

so what d pump does is pushes the sodium outside and gets potassium in...so if thats not working then the charge separation accross the membrane is hampered and this in turn affects many processes....for eg receiving a signal from a neuron...

Answer 90

so？

Answer 91

so thats it..:P
isnt this enuf? or u need more?

Answer 92

i want know what will the rest potential change since the Na+K+pumps are distroied.

Answer 93

u want to know d value?

Answer 94

i want to know whether the potential will be more negative or less negative