Sodium Potassium Pump's Activity

[chrisnikk]

If we increase or decrease the Na+/K+ ATPase's activity (Sodium Potassium Pump) what would happen to the membrane potential?

[Velocity_Boy]

If we increase or decrease the Na+/K+ ATPase's activity (Sodium Potassium Pump) what would happen to the membrane potential?

 

 

The cell membrane is depolarized.....So it becomes closer to a 0 V potential difference of charge...both inside and outside the cell?

[Function]

The cell membrane is depolarized.....So it becomes closer to a 0 V potential difference of charge...both inside and outside the cell?

 

It seems you don't get the hang of membrane potentials. A potential is a difference of charge between 2 points. Here, we consider the membrane potential being the difference of charge in v. out of the cell. The more positively charged your cell (cytoplasm) is, the more positive the membrane potential is.

 

If we increase or decrease the Na+/K+ ATPase's activity (Sodium Potassium Pump) what would happen to the membrane potential?

 

Basically, the Na/K-ATPase exchanges 3 intracellular Na-ions for 2 extracellular K-ions.

 

Note that normally, there is a higher concentration of Na extracellular and a higher intracellular concentration of K (no. [Na]i = 15 mM; [Na]e = 145 mM; [K]i = 150 mM; [K]e = 4 mM). However, due to other Na and K channel activities, they may leak from (K) or into (Na) the cell.

 

The Na/K-ATPase tries to correct this by actively pumping Na back out of the cell, and K back into the cell.

 

You notice that the net charge movement is 1 positive ion out of the cell: (3 + out) + (2 + in) = 1 + out

 

Result: a net hyperpolarization of your cell membrane.

 

The membrane potential is considered as the difference of charge in the cell minus that out of the cell, at the level of the cell membrane.

 

If you put more positively charged ions out of the cell, your membrane potential becomes more negative and as a net result, you get a hyperpolarization.

 

In most tissues, this results in a reduced excitability.

Edited April 1, 2017 by Function