Problem:

The Na+ -glucose symport system of intestinal epithelial cells couples the "downhill" transport of two Na+ ions into the cell to the "uphill" transport of glucose, pumping glucose into the cell against its concentration gradient. If the Na+ concentration outside the cell ([Na ]out) is 151 mM and that inside the cell ([Na ]in) is 19.0 mM, and the cell potential is -49.0 mV (inside negative),

Required:

Question: calculate the maximum ratio of [glucose]in to [glucose]out that could theoretically be produced if the energy coupling were 100% efficient. Assume the temperature is 37 °C.

Show the pedigree and your calculation.