Why is sodium potassium pump required?

[scilearner]

Ok I searched and found this as the answer from a previous topic

 

"The sodium potassium pump is required to maintain osmotic balance and stabilize the cells volume. If you treat an animal cell with ouabain, which inhibits the Na+/K+ pump, it will swell and often burst.

 

Cells contain mostly negatively charged organic molecules, so they require cations for a counter charge balance: K+. This will create a large osmotic gradients, that would pull water into the cell, so it will pump out Na+.

 

The pump is also able to generate membrane potential in nerve cells because of its electrogenic effect, but 90% of the membrane potential depends indirectly on the Na+/K+ pump."

 

Questions I have

 

1. Why do cells mostly contain negative charge. If this is due to proteins. What are the proteins inside cells.

2. So my understanding is that K+ and Na+ try to neutralize the negative charge inside the cell. To reduce the solute concentration Na+ is sent out or else the cell would burst. I think this is wrong. Can someone please explain this to me.

3. For nerve cells what membrane potential do they need. Do they want the inside of the cell to be negative.

 

Thank you very much

[granpa]

sodium is poisonous. cells pump it out and then pump in potassium to balance the charge.

 

any ions forming a net charge within the cell should form a thin layer under the cell membrane and should be balanced by a thin layer of changes on the outside of the membrane.

 

even with the sodium potassium pumps turned off the neuron can still fire hundreds of thousands of times.