Biochemistry 4th Edition by Reginald Garrett, Charles Grisham

Exercise 10

Determining the concentration limits of an active transport system
(Integrates with Chapter 3.) Fructose is present outside a cell at 1 µM concentration. An active transport system in the plasma membrane transports fructose into this cell, using the free energy of ATP hydrolysis to drive fructose uptake. What is the highest intracellular concentration of fructose that this transport system can generate Assume that one fructose is transported per ATP hydrolyzed; that ATP is hydrolyzed on the intracellular surface of the membrane; and that the concentrations of ATP, ADP, and Pi are 3 mM, 1 mM, and 0.5 mM, respectively. T=298 K (Hint: Refer to Chapter 3 to recall the effects of concentration on free energy of ATP hydrolysis.)