Question

ATPase - Na/K ATPase pump , action potential
I have read that Na is released in to the extra cellular matrix as a 1st step and then other times I read that Na is sent to the mitochondria in the 1st step .. what am I missing?

Answer 1

The Na/K ATPase pump's primary function is to control a cell's volume when placed in a stressful environment. It does this by, as you probably know, changing the membrane potential of the cell. It does this on the plasma membrane by regulating when to activate the pump and let more Na out then K in (3:2) thereby making the cell more negatively charged.

This is an example of active transport, meaning it needs ATP to do this.

The mitochondrial inner membrane isn't involved whatsoever.

Hope this clears things up.

Answer 2

@desy
You have two completely different pumps confused, ATPase is also known as Complex V in oxidative phosphorylation. i'll try to draw you a simple schematic.
Basically put, the NADH+H & FADH2 from glycolysis & Citric acid cycle are pumped out to create a concentration gradient which is utilized by ATPase (Complex V) to create ATP.