Question Electric potential inside a living cell is 0.075V lower than the electric potential ouside the cell. Thickness of membrane is 120nm. a) What is the magnitude and direction of the electric field within the cell membrane? Possible Ans: Is this just use the forumula E = -dV/ds = 6.25 x 10^5 V/m and its directed out b) For a cell of thickness 150nm and the same electric potential as above, calculate the work done (in joules) to move one sodium ion from inside of the cell to outside. Possible Ans: Is this using the forumla W = -qEs If it is what charge will I use for q? or is it just +1?