Biological systems need to conserve order, but they do this at the expense of their environment. Lots of energy in reactants, little energy in products, energy released during reaction. Reactants without much energy, energy is added, products are energy rich. G. Equilibrium constant K eq 1. Tells you which way a reaction will go, spontaneously.
Reaction goes to the right.
Lots of products. Reaction goes to the left. Lots of reactants. If all the reactions inside a cell reach equilibrium, no work could be done. So, cells try to approach equilibrium without ever reaching it.