Active Transport of Na/K pump

[Wererew]

If the Na/K pump is an active transport system, wouldn't there be more Na outside of the cell than inside since it is pumping inside to outside of the cell? If the pump is inhibited, why is the [Na] higher inside the cell anyway? Simply from Na ions not being able to pump out?

Would it depend what stage (resting potential, depolarization,,etc) the cell is at?

Any clarification is appreciated 🙂

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[artist2022]

If the Na/K pump is an active transport system, wouldn't there be more Na outside of the cell than inside since it is pumping inside to outside? If the pump is inhibited, why is the [Na] higher inside the cell anyway? Simply from Na ions not being able to pump out?

Would it depend what stage (resting potential, depolarization,,etc) the cell is at?

Any clarification is appreciated 🙂

Yes, if the pump is working then there would be more Na outside than inside. If the pump is inhibited, then ions won't be pumped out and also they'd follow their concentration gradient and flow back in.
The Na/K pump has nothing to do with nerve signal transmission (those are voltage-gated Na and K channels doing the depolarization, repolarization)

 

[Wererew]

Yes, if the pump is working then there would be more Na outside than inside. If the pump is inhibited, then ions won't be pumped out and also they'd follow their concentration gradient and flow back in.
The Na/K pump has nothing to do with nerve signal transmission (those are voltage-gated Na and K channels doing the depolarization, repolarization)

Ohhh thanks for clarifying that! Right, voltage-gated have single Na and K individual pumps...

For the Na/K pump, why is it active transport if it is flowing from higher to lower concentration of Na ions? Or is it originally low to high, but when it is inhibited there is a build up of the ions?

 

[artist2022]

Ohhh thanks for clarifying that! Right, voltage-gated have single Na and K individual pumps...

For the Na/K pump, why is it active transport if it is flowing from higher to lower concentration of Na ions? Or is it originally low to high, but when it is inhibited there is a build up of the ions?

You're welcome! And it is active transport because the Na ions are flowing from low concentration (inside the cell) to high concentration (outside the cell). This requires energy. When the pump is inhibited, it is no longer creating/maintaining this gradient, so the ions will flow from high concentration (outside the cell) to a low concentration (inside the cell) via facilitated diffusion.

 

[Wererew]

You're welcome! And it is active transport because the Na ions are flowing from low concentration (inside the cell) to high concentration (outside the cell). This requires energy. When the pump is inhibited, it is no longer creating/maintaining this gradient, so the ions will flow from high concentration (outside the cell) to a low concentration (inside the cell) via facilitated diffusion.

Thank you!!

 

[tyjacobs]

If the Na/K pump is an active transport system, wouldn't there be more Na outside of the cell than inside since it is pumping inside to outside of the cell? If the pump is inhibited, why is the [Na] higher inside the cell anyway? Simply from Na ions not being able to pump out?

Would it depend what stage (resting potential, depolarization,,etc) the cell is at?

Any clarification is appreciated 🙂

Great question.

So the Na/K ATPase is a very important pump in the cell. It is an active transport pump that uses the energy of ATP hydrolysis to drive its function. Extracellular Na is infact higher outside of the cell than inside of the cell because of this pump when it is functioning normally.

When does Na/K ATPase not function normally?
1. use an inhibitor (i.e. the drug digoxin, a treatment for heart failure)
2. alter the concentration gradient of sodium by altering the function of other sodium channels on the cell membrane. If the concentration gradient between outside and inside is even larger, then Na/K ATPase function will decrease because it will require even more energy to drive Na/K ATPase function (yet the energy supply from ATP remains constant)