Subject: Do these ion pumps lower activation energy?

In anatomy and physiology, we went over the definition of nerve impulse 
(action potentials) when the stimulus exceeds the threshold, causing Na 
cation channels to open and depolarization occurs.  In several diagrams, 
they show the "outside" with an overall positive charge, and the "inside" 
as an overall negative charge.  Of course, as a chemistry major, I'd love 
to know why these cations are free to move back and forth, and are 
seemingly non-reactive with their surroundings, but my main question is 
this:  the ion "pumps" that serve to change overall charges to create the 
nerve impulse remind me of the old lowering of activation energy diagrams, 
illustrating catalysts.  Are these pumps catalysts or is there a simpler 
explanation?  Thanks in advance.

Re: Do these ion pumps lower activation energy?