The hydrolysis of glucose 6-phosphate in aqueous solution at is represented by…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
The hydrolysis of glucose 6-phosphate in aqueous solution at 298K is represented by
Glucose 6-phosphate+H2O⇌Glucose+PiΔG∘=+13.8kJmol−1
Hydrolysis of ATP under the same conditions is
ATP+H2O⇌ADP+Pi+H+ΔG∘=−30.5kJmol−1
A metabolic engineer wants to use ATP hydrolysis to drive the unfavorable hydrolysis of glucose 6-phosphate so that the overall process is strongly spontaneous.
(1) Part 1: (a) Write the chemical equation obtained when one mole of ATP hydrolysis is coupled to one mole of glucose 6-phosphate hydrolysis. Cancel any intermediates and show the net stoichiometry.
(2) Part 2: (b) Calculate the overall ΔG∘ when one mole of ATP is coupled as in part (a). Show your work with units.
(3) Part 3: (c) Determine the minimum integer number of moles of ATP that must be hydrolyzed per mole of glucose 6-phosphate so that the overall ΔG∘ is at most −10kJmol−1. Explain your reasoning.
(4) Part 4: (d) Discuss qualitatively how increasing the cellular temperature from 298K to 310K could influence the spontaneity of the coupled reaction, assuming ΔH∘ and ΔS∘ for each individual reaction remain approximately temperature-independent over this range.