The inner and outer surfaces of a cell membrane carry a negative and positive charge, respectively. Because of these charges, a potential difference of about 70 mV exists across the membrane. The thickness of the membrane is 8 nm. A) If the membrane were empty (filled with air), what would be the magnitude of the electric field inside the membrane? (Assume that this field would be constant in magnitude). B) If the dielectric constant of the membrane is K = 3, what would the field be inside the membrane?3) Cells can carry ions across a membrane against the field ("uphill") using a variety of active transport mechanisms. One mechanism does so by using up some of the cell's stored energy (converting ATP to ADP, for those who remember their biochemistry). How much work does it take to carry one sodium ion (charge = +e) across the membrane against the field?