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A2 Biology - Function of sodium and potassium pumps in action and resting potentials

So far, I have no clue as to how they contribute to an action and resting potential. All resources talk about them maintaining the distribution of sodium and potassium ions, but how? When ? And if they are pumping sodium and potassium ions, won't this affect the potential difference across the cell membrane of the axon of the neurone whilst sodium ions and potassium ions move through?

HELP PLSSSSSSSSSSSSs
Original post by sweetescobar
So far, I have no clue as to how they contribute to an action and resting potential. All resources talk about them maintaining the distribution of sodium and potassium ions, but how? When ? And if they are pumping sodium and potassium ions, won't this affect the potential difference across the cell membrane of the axon of the neurone whilst sodium ions and potassium ions move through?

HELP PLSSSSSSSSSSSSs

OMG just had a test on this :frown:
Anyway, from what I understand, the sodium-potassium pump does help maintain the resting potential by pumping 3 Na out of the axon and 2 K into the axon; this creates a higher concentration of Na ions outside of the axon than inside, and a higher concentration of K ions inside the axon than outside.
This creates an electrochemical gradient which, when stimuli significant enough exceed the threshold value, reverses the flow of ions.
When the Na protein channels open, leading to an influx of Na ions via facilitated diffusion - which generates an action potential.

Resting potential is maintained as the inside of the axon is more negative than the outside ( due to the active transport of the Na and K ions) thus making the potential difference of the axon to be - 65mv.

Hopefully, that answers your question :smile:
Seems like we're in the same boat!
If you don't mind me asking what are you applying to for uni?
Yooo just saw this. Thx a lottt btw. I applied to Hull York, Queens, Kings college and Bristol wbu? Literally jumped on here to find teh interview formats for the unis
Original post by sweetescobar
So far, I have no clue as to how they contribute to an action and resting potential. All resources talk about them maintaining the distribution of sodium and potassium ions, but how? When ? And if they are pumping sodium and potassium ions, won't this affect the potential difference across the cell membrane of the axon of the neurone whilst sodium ions and potassium ions move through?

HELP PLSSSSSSSSSSSSs


The sodium-potassium pump has a very small effect on the resting membrane potential. It is often believed that the resting membrane potential is established because the sodium -potassium pump pumps 3 Na+ and 2K+ in. Yes, it is important in maintaining the electrochemical gradients, but it does not establish them. The resting membrane potential is determined by the the fact that the membrane is around 40 times more permeable to potassium than it is to sodium through leak channels.
Original post by sweetescobar
Yooo just saw this. Thx a lottt btw. I applied to Hull York, Queens, Kings college and Bristol wbu? Literally jumped on here to find teh interview formats for the unis

Heyyy, sry for the late reply 😅
I applied to keele, lincoln, Nottingham, Birmingham and Aston.
Wht course did u apply for?

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