Question

Fructose‑2,6‑bisphosphate is a regulator of both glycolysis and gluconeogenesis for the phosphofructokinase reaction of glycolysis and the fructose‑1,6‑bisphosphatase reaction of gluconeogenesis. In turn, the concentration of fructose‑2,6‑bisphosphate is regulated by many hormones, second messengers, and enzymes. Classify each condition according to its effect on glycolysis and gluconeogenesis Activates glycolysis and inhibits gluconeogenesis Activates gluconeogenesis and inhibits glycolysis

Answer 1

Fructose-2,6-bisphosphate activates glycolysis and inhibits gluconeogenesis when present, while activating gluconeogenesis and inhibiting glycolysis when absent or at low levels.

Step-by-step explanation:

Fructose-2,6-bisphosphate plays a regulatory role in both glycolysis and gluconeogenesis. When fructose-2,6-bisphosphate is present, it activates glycolysis and inhibits gluconeogenesis. On the other hand, when fructose-2,6-bisphosphate is absent or at low levels, it activates gluconeogenesis and inhibits glycolysis.

For example, when a hormone or second messenger increases the concentration of fructose-2,6-bisphosphate, it will stimulate glycolysis while suppressing gluconeogenesis. Conversely, when the concentration of fructose-2,6-bisphosphate decreases, it will stimulate gluconeogenesis and inhibit glycolysis.