Question

# Standard Free Energy of Hydrolysis, ∆ G o', of some organophosphate compounds (phosphate isreleased as one...

Standard Free Energy of Hydrolysis, ∆ G o', of some organophosphate compounds (phosphate isreleased as one of the products of hydrolysis)

 Compound kJ/mol phosphoenolpyruvate -61.9 carbamyl phosphate -51.4 creatine phosphate -43.1 acetyl phosphate -42.2 ATP (to ADP) -30.5 Glucose-1-phosphate -20.9 Glucose-6-phosphate -13.8 Glycerol-3-phosphate -9.2

Use the table in the above table to calculate the ∆G o' (in kJ/mol) for the following reaction:

ATP +  glucose --------> ADP  +  glucose-6-phosphate

Given reaction , occurs in two steps.

1) ATP + H2O -> ADP + phosphate

For this reaction of hydrolysis of ATP ,from table

ΔGo1 = -30.5 KJ/ mol.

2) Glucose + phosphate -> Glucose - 6 - Phosphate + H2O

This reaction is reverse to hydrolysis of glucos - 6 - phosphate.

So , for this reaction ΔGo2 = - ( - 13.8) = +13.8 KJ/mol

So for overall reaction of

ATP+ Glucose -> ADP + Glucose -6- phosphate

ΔGo =  ΔGo1 + ΔGo2

= -30.5 +13.8

= - 16.7 KJ/ mol.