' At the peak of the graph, Is the concentration of Na outside the cell is more than inside? because that must be to overcome the electrical force in the opposite direction but my book says that that inside the cell there are more Na than outside When is the concentration of Na+ greatest inside the cell? At the peak assuming the Na+ channel close immediately at it then it is also greatest at 3. If there is still passage of Na+ then 3 is the maximum ( Is that right?) One last question, is the inside of membrane actually negative, or only negative relative to the outside? In a galvanic cell for example, a given rod isn't actually negative, but it is negative relative to another. Then why do they say that there are some negative proteins inside the cell that makes the negative charge?