1. You are studying a reaction wherein compound X is dehydrogenated to yield compound Y, and in the absence of a catalyst you have determined that the ?Go under standard conditions of pH 7 and 37o (RT = 0.59 kcal/mole) has a value of +0.7 kcal/mole.
A. (4 pts) If you start with 100,000 molecules of X, how much, if any, Y will be generated when you reach equilibrium? Explain your answer.
B. (6 pts) You have isolated an enzyme that catalyzes this reaction by coupling it to the hydrolysis of a high energy intermediate. At equilibrium, only 650 molecules of X remain from the initial 100,000 molecules. Given the following table of ?Go for the hydrolysis of three phosphate-containing compounds, which of these three compounds is the least wasteful energy source for the coupled reaction?
Reaction
Hydrolysis of phosphoenolpyruvate has a deltaGo of -14.8 kcal/mol
Hydrolysis of ATP to ADP + Pi has a deltaGo of -7.3 kcal/mol
Hydrolysis of glucose 6-phosphate has a deltaGo of -3.3 kcal/mol