ATP hydrolysis

[mario0923]

so I know we had a thread on ATP hydrolysis
and I am the one of people who answered the questions
but I have another question

ATP hydrolysis ATP->ADP+Pi+energy
is an exergonic reaction and this reaction is used as "energy source" by coupling reactions where ATP hydrolysis is coupled with other endergonic reactions to make the endergonic reaction happen.

But does the energy of ATP hydrolysis lowers the Activation Energy of the endergonic reaction or does it lower the Free Energy of the endergonic reaction?

I thought ATP hydrolysis lowers the activation energy but I saw in a sample test explanation ( I think Achiever...I don't remember and I can't find it anymore) that the correct answer was lowering free energy.
If I am correct, the Free Energy released by ATP hydrolysis lowers the Activation Energy of the endergonic reaction right?

---

Members don't see this ad.

 

[Mr. Thirsty]

ATP provides the energy to overcome the activation energy. Only enzymes can lower activation energy. ATP lowers free energy because it makes the reaction become "more spontaneous" or more favorable. Free energy isn't necessarily "released"; its a broader term that is generally defined as being and overall value, either + (endergonic) or more - (exergonic).

 

[ballyhoo]

Hm. Does ATP change the free energy by changing the dH then?