Living cells actively“pump” positive sodium ions 1Na+2 from inside the cell to outsidethe cell. This process is referred to as pumping because work mustbe done on the ions to move them from the negatively chargedinner surface of the membrane to the positively charged outer surface. Given that the electric potential is 0.070 V higher outside thecell than inside the cell, and that the cell membrane is 0.10 mmthick, (a) calculate the work that must be done (in joules) to moveone sodium ion from inside the cell to outside. (b) If the thickness of the cell membrane is increased, does your answer to part (a)increase, decrease, or stay the same? Explain. (It is estimated thatas much as 20% of the energy we consume in a resting state is usedin operating this “sodium pump.”)
Living cells actively
“pump” positive sodium ions 1Na+2 from inside the cell to outside
the cell. This process is referred to as pumping because work must
be done on the ions to move them from the negatively charged
inner surface of the membrane to the positively charged outer surface. Given that the electric potential is 0.070 V higher outside the
cell than inside the cell, and that the cell membrane is 0.10 mm
thick, (a) calculate the work that must be done (in joules) to move
one sodium ion from inside the cell to outside. (b) If the thickness of the cell membrane is increased, does your answer to part (a)
increase, decrease, or stay the same? Explain. (It is estimated that
as much as 20% of the energy we consume in a resting state is used
in operating this “sodium pump.”)
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 1 images
