Why does glycolysis and gluconeogenesis both have ve gibbs f

Why does glycolysis and gluconeogenesis both have -ve gibbs free energy ?

Solution

Gibbs free energy change is negative for all those reactions which are favourable and occur spontaneously.

In glycolysis pathway , some steps have negative free energy change and some have positive free energy change so overall the gibbs free energy change becomes negative for the reaction . And the reaction becomes favourable.

In gluconeogenesis, the enzymes perform bypass reactions which have very less energy barrier instead of the reverse glycolysis reactions that requires high amount of energies. So it uses 7 enzymes from glycolysis and 4 other enzymes . So both reactions though have negative free energy change but can\'t occur at same place simultaneously. They may occur in different organs at the same time.