Before attempting this one, see Insight 16.1, Electric Potential and Nerve Signal Transmission and Learn by Drawing 16.2 on graphical relationships between and V. Suppose an (axon) cell membrane is experiencing the end of a stimulus event and the voltage across the cell membrane is instantaneous at 30 mV. Assume the membrane is 10 nm thick. At this point the Na/K-ATP ase molecular pump starts to move the excess ions back to the exterior.
(a) How much work does it take for the pump to move the first sodium ion?
(b) Estimate the electric field (including direction) in the membrane under these conditions.
(c) Estimate the force on that first sodium ion.
(d) What is the electric field (including direction) under normal conditions when the voltage across the membrane is – 70mV?