Based upon the following reactions, what would be the ΔG°′ for the formation of ATP from phosphoenolpyruvate and ADP?
ATP → ADP + Pi
ΔG°′ = −31.5 kJ/mol
Phosphoenolpyruvate → pyruvate + Pi
ΔG°′ = −62.2 kJ/mol
A) −93.7 kJ/mol
B) −30.7 kJ/mol
C) +30.7 kJ/mol
D) +93.7 kJ/mol
E) cannot determine from given information

Question

Quizplus · Accepted Answer

To find the ΔG°′ for the formation of ATP from phosphoenolpyruvate and ADP, we need to reverse the first reaction (which changes the sign of ΔG°′) and then add it to the second reaction. Reversing the first reaction gives us +31.5 kJ/mol, and adding this to the second reaction's ΔG°′ of −62.2 kJ/mol gives us −30.7 kJ/mol.

Based Upon the Following Reactions, What Would Be the ΔG°′