Answer:
both reactions need to be exergonic. the exergonic reaction needs to release more energy than the endergonic reaction requires
Step-by-step explanation:
In exergonic reaction the energy is being released by the body to surroundings and in endergonic reaction the energy is being absorbed by the body from the surroundings.
Now in order to proceed a reaction the free energy change should be negative so the reaction should be exothermic in all. During coupling of two reactions the possible combinations for feasibility of a reaction are:
a) the two reactions are exergonic
b) one of the reaction is exergonic with higher energy release than the other endergonic reaction.