Glükoneogenezissel

Glükoneogenezissel is the metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. This process occurs primarily in the liver and kidney. It is a crucial pathway for maintaining blood glucose levels, especially during periods of fasting, starvation, or intense exercise when glucose intake is insufficient. The substrates for gluconeogenesis include pyruvate, lactate, glycerol, and certain amino acids.

The gluconeogenic pathway is largely the reverse of glycolysis, but it involves several unique enzymes that bypass the energetically irreversible steps of glycolysis. For instance, pyruvate carboxylase, phosphoenolpyruvate carboxykinase, and fructose-1,6-bisphosphatase are key enzymes that facilitate the conversion of pyruvate back to glucose. The energy for gluconeogenesis is supplied by the hydrolysis of ATP and GTP.

Hormonal regulation plays a significant role in controlling gluconeogenesis. Glucagon, a hormone released when blood glucose levels are low, stimulates gluconeogenesis. Conversely, insulin, released when blood glucose levels are high, inhibits this pathway. This hormonal interplay ensures that glucose homeostasis is maintained. Disorders affecting gluconeogenesis can lead to hypoglycemia or hyperglycemia, highlighting its importance in metabolic health.