If the enzyme phosphohexoisomerase is added to a 0.3 M solution of fructose 6-phosphate and the reaction is allowed to proceed to equilibrium, the final concentrations are 0.2 M glucose 6-phosphate and 0.1 M fructose 6-phosphate.What would be the final concentration of glucose 6-phosphate if the initial concentration of fructose 6-phosphate were changed to 3 M?

Question

Quizplus · Accepted Answer

The enzyme phosphohexoisomerase catalyzes the interconversion of fructose 6-phosphate and glucose 6-phosphate until the reaction reaches equilibrium. Therefore, the ratio of glucose 6-phosphate to fructose 6-phosphate will always be the same when the reaction has reached equilibrium, regardless of the initial concentration of fructose 6-phosphate. In this particular case, when starting with 0.3 M fructose 6-phosphate, we end up with a 2:1 ratio between glucose 6-phosphate and fructose 6-phosphate. If we increase the concentration of fructose 6-phosphate to 3 M and run the same reaction, we would still end up with a 2:1 ratio between glucose 6-phosphate and fructose 6-phosphate, which corresponds to a final concentration of 2 M glucose 6-phosphate (since the total concentration of both hexose phosphates is 3 M and the ratio is 2:1). Therefore, the correct answer is A) 2 M.

If the Enzyme Phosphohexoisomerase Is Added to a 0