The ΔG of ATP hydrolysis in a test tube under standard conditions is -7.3 kcal/mol. The ΔG for the reaction A + B = C under the same conditions is +4.0 kcal/mol. What is the overall free-energy change for the coupled reactions under these conditions?
A) -11.3 kcal/mol.
B) -7.3 kcal/mol.
C) -3.3 kcal/mol.
D) +3.3 kcal/mol.

Question

Quizplus · Accepted Answer

To find the overall free-energy change for the coupled reactions, you add the ΔG values of the individual reactions. So, -7.3 kcal/mol (for ATP hydrolysis) + 4.0 kcal/mol (for reaction A + B = C) equals -3.3 kcal/mol.

The ΔG of ATP Hydrolysis in a Test Tube Under