Which of the Following Compounds Would Liberate the Most Free

Question

Which of the following compounds would liberate the most free energy on hydrolysis?
A) ATP
B) Phosphoenolpyruvate
C) PPi
D) ADP
E) GTP

Accepted Answer

Phosphoenolpyruvate (PEP) is known to have one of the highest free energy changes upon hydrolysis among the compounds listed. This high energy change is due to the enol phosphate group it contains, making it a very high-energy phosphate compound, even more so than ATP or GTP.