Relationship of free energy change | Quick Homework Help
The relationship of free energy change (?G) to the concentrations of reactants and products is important because it predicts the direction of spontaneous chemical reactions. Familiarity with this relationship is essential for understanding energy conversions in cells. Consider for example the hydrolysis of ATP to ADP and inorganic phosphate (Pi): ATP + H20 ? ADP + Pi The free energy change due to ATP hydrolysis is ?G = ?Go + RT ln [ADP] [Pi] [ATP] = ?Go + 2.3 RT log [ADP] [Pi] [ATP] A. Calculate the ?G for ATP hydrolysis when the concentration of ATP, ADP and Pi are all equal to 1mM. What is ?G when the concentration of ATP, ADP, and Pi when the concentrations of ATP, ADP and Pi are all equal to 2M? B. What will ?G equal when the hydrolysis reaction reaches equilibrium? At [Pi] = 5mM, what will be the ratio of [ATP] to [ADP] at equilibrium C. Show that, at a constant [Pi] , ?G decreases by 1.4kcal/mole for every 10-fold increase in the ration of [ATP] to [ADP], regardless of the value of ?Go.
