the reaction converting glycerol to glycerol-3-phosphate is energetically unfavourable by 9.2 kj mol−1 . the reaction of atp with water to yield adp, hydrogen phosphate ion, and hydrogen ion is energetically favourable by 30.5 kj mol−1 . these reactions are coupled so that the overall process is energetically favourable. what is δrg for the overall process?
To determine δrg for the overall process, we need to understand the concept of Gibbs free energy change (ΔG). ΔG is a measure of the spontaneity and energetics of a chemical reaction. A negative ΔG indicates that the reaction is energetically favorable and spontaneous, while a positive ΔG indicates an energetically unfavorable reaction.
In this case, we have two reactions that are coupled together to form the overall process. The reaction converting glycerol to glycerol-3-phosphate is energetically unfavorable by 9.2 kJ/mol, while the reaction of ATP with water to yield ADP, hydrogen phosphate ion, and hydrogen ion is energetically favorable by 30.5 kJ/mol.
When reactions are coupled in a process, the ΔG values of the individual reactions can be added together to obtain the ΔG for the overall process. Therefore, δrg for the overall process can be calculated as follows:
δrg = ΔG1 + ΔG2
Where ΔG1 is the ΔG value for the reaction converting glycerol to glycerol-3-phosphate (-9.2 kJ/mol) and ΔG2 is the ΔG value for the reaction of ATP with water (30.5 kJ/mol).
Substituting the values, we have:
δrg = (-9.2 kJ/mol) + (30.5 kJ/mol)
= 21.3 kJ/mol
Therefore, δrg for the overall process is 21.3 kJ/mol. Since the value is positive, it indicates that the overall process is energetically favorable.