These enzymes only catalyse the reaction in one direction each, and are regulated by metabolites such as fructose 2,6-bisphosphate so that high activity of one of the two enzymes is accompanied by low activity of the other.
Estes dous encimas só catalizan a reacción nunha reacción, e son regulados por metabolitos como a frutosa 2,6-bisfosfato para que a actividae alta dun dos encimas vaia acompañada da actividade baixa do outro.