General ATP/GTP question

[treeclimbingmonkey]

This might kind of be a silly question, but is ATP or GTP hydrolysis endothermic or exothermic?
I know bond breaking is an endothermic process and bond forming is an exothermic process. But why is energy released upon hydrolysis of ATP or GTP. Wouldn't that be an exothermic process?

---

Members don't see this ad.

 

[Blueprint Med School]

Yes, hydrolysis of ATP/GTP is exothermic. When bonds break, the energy held within the bond is released, so bond breaking is exothermic. When bonds are formed, energy has to be put in to create the bond, so bond forming is endothermic.

Kevin W, MCAT Tutor
Med School Tutors

 

[treeclimbingmonkey]

Yes, hydrolysis of ATP/GTP is exothermic. When bonds break, the energy held within the bond is released, so bond breaking is exothermic. When bonds are formed, energy has to be put in to create the bond, so bond forming is endothermic.

Kevin W, MCAT Tutor
Med School Tutors

But on this EK Question it says endothermic?

 

[JimKimSlim]

i don’t like this problem. the PROCESS of breaking the bond needs energy and hence endothermic, but process of building the bond is exothermic. Since in ATP/GTP hydrolysis the energy output of building the bond is greater than energy input of breaking the bond, the overall reaction is exothermic (Look up ATP hydrolysis free energy diagram).

 

[treeclimbingmonkey]

i don’t like this problem. the PROCESS of breaking the bond needs energy and hence endothermic, but process of building the bond is exothermic. Since in ATP/GTP hydrolysis the energy output of building the bond is greater than energy input of breaking the bond, the overall reaction is exothermic (Look up ATP hydrolysis free energy diagram).

I will look it up! I didn't like this question either. :/
Thank you!