MUSCLE PHYSIOLOGY

Detailed explanation-1: -Phosphofructokinase is activated by AMP and fructose-2, 6-bisphosphate and inhibited by ATP, while fructose-1, 6-bisphosphatase is regulated in the opposite manner by the same intermediates. The result is a coordinated control of carbon flux via glycolysis and gluconeogenesis in the liver.

Detailed explanation-2: -Fructose-2, 6-bisphosphate (F2, 6BP) is a shunt product of glycolysis that allosterically activates 6-phosphofructo-1-kinase (PFK-1) resulting in increased glucose uptake and glycolytic flux to lactate.

Detailed explanation-3: -Elevated expression of Fru-2, 6-P2 levels in the liver allosterically activates phosphofructokinase 1 by increasing the enzyme’s affinity for fructose 6-phosphate, while decreasing its affinity for inhibitory ATP and citrate.

Detailed explanation-4: -Fructose-1, 6-Bisphosphatase (FBPase) The enzyme is regulated allosterically by a number of small molecules including AMP and fructose-2, 6-phosphate, which are negative regulators, and ATP that is a positive regulator.

Detailed explanation-5: -Metformin reduces liver glucose production by inhibition of fructose-1-6-bisphosphatase.