The standard free-energy changes for the reactions below are given. phosphocreatine $\rightarrow$ creatine + P_i
$\Delta$ G'° = -43.0 kJ/mol
ATP $\rightarrow$ ADP + P_i
$\Delta$ G'° = -30.5 kJ/mol
What is the overall $\Delta$ G'° for the following reaction?
Phosphocreatine + ADP $\rightarrow$ creatine + ATP

Question

The standard free-energy changes for the reactions below are given. phosphocreatine

\rightarrow

creatine + P_i

\Delta

G'° = -43.0 kJ/mol
ATP

\rightarrow

ADP + P_i

\Delta

G'° = -30.5 kJ/mol
What is the overall

\Delta

G'° for the following reaction?
Phosphocreatine + ADP

\rightarrow

creatine + ATP

Quizplus · Accepted Answer

To find the overall $\Delta G'^\circ$ for the reaction Phosphocreatine + ADP $\rightarrow$ Creatine + ATP, we add the $\Delta G'^\circ$ values of the given reactions, taking into account the direction of the reactions. The $\Delta G'^\circ$ for the conversion of phosphocreatine to creatine is -43.0 kJ/mol, and for ATP to ADP is -30.5 kJ/mol. Since the desired reaction involves the reverse of the ATP to ADP conversion, we reverse the sign of its $\Delta G'^\circ$ value, making it +30.5 kJ/mol. Adding these together: -43.0 kJ/mol + 30.5 kJ/mol = -12.5 kJ/mol.

The Standard Free-Energy Changes for the Reactions Below Are Given →\rightarrow→

The Standard Free-Energy Changes for the Reactions Below Are Given $\rightarrow$