Regulation of gluconeogenesisGluconeogenesis and glycolysis are coordinated so that within a cell one pathway is relatively inactivewhile the other is highly active. If both sets of reactions were hig

Regulation of gluconeogenesisGluconeogenesis and glycolysis are coordinated so that within a cell one pathway is relatively inactivewhile the other is highly active. If both sets of reactions were highly active at the same time, the net resultwould be the hydrolysis of four nucleotide triphosphates (two ATP plus two GTP) per reaction cycle.Both glycolysis and gluconeogenesis are highly exergonic under cellular conditions, and so there is nothermodynamic barrier to such simultaneous activity. However, the amounts and activities of thedistinctive enzymes of each pathway are controlled so that both pathways are not highly active at thesame time. The rate of glycolysis is also determined by the concentration of glucose, and the rate ofgluconeogenesis by the concentrations of lactate and other precursors of glucose.