A The nerve cell does not look like our usual parallel plate capacitor, it looks like a cylinder. But you can think of it as two parallel plates that have been rolled up. (Try to picture it!). Below we show this model, thinking of the outside and inside of the membrane as the two plates. Outside Membrane KKKKKKKKKKKK KKK The Membrane Axon Side The magnitude of the potential difference across the membrane in the resting state is about 80 mV. Which region is at the lower potential, the inside or the outside? Please briefly explain your reasoning. (2 points) What is the magnitude of the electric field inside the membrane? Show your algebraic work and your numerical answer. (2 points) C In addition to the K and Cl ions stuck to the membrane, there are also Na ions inside the nerve cell. In its resting state, the nerve pumps Na ions, each a positive charge (te), out of the cell, through the membrane, to the outside fluid. Does the nerve cell do positive or negative work on the Na ions during this transfer? Please briefly explain your reasoning. (2 points) University of Colorado Boulder, Department of Physics Name How much work is done against the electric field to carry one single Na ion across the membrane? Instead of Joules, give your answer in units more commonly used in biophysics: electron volts (eV). To convert: 1 ev = 1.6 x 10-19 /. (2 points) E OPTIONAL: Many of you know much more biology than I do, and I am always looking to learn new things (and improve these homework assignments). Were there any aspects of the biology in this problem set that struck you as incomplete, confusing, or oversimplified? Anything interesting you think I might want to know about ion transport and cell membranes