glükoneogeneesist

Glukoneogeneesist 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, and to a lesser extent in the small intestine. Glukoneogeneesist is essential for maintaining blood glucose levels during periods of fasting, starvation, or prolonged exercise when dietary carbohydrate intake is insufficient. The substrates for glukoneogeneesist include lactate, pyruvate, glycerol, and certain amino acids.

The pathway is a complex series of enzymatic reactions that essentially reverses glycolysis. However, it is not a simple reversal due to the irreversible nature of three key steps in glycolysis. These steps are bypassed in glukoneogeneesist by different enzymes that facilitate the conversion of pyruvate back into phosphoenolpyruvate, fructose-1,6-bisphosphate into fructose-6-phosphate, and glucose-6-phosphate into glucose. The major regulatory enzyme of glukoneogeneesist is fructose-1,6-bisphosphatase.

Hormonal regulation plays a crucial role in controlling glukoneogeneesist. Glucagon and cortisol stimulate the pathway, promoting glucose production, while insulin inhibits it. This ensures that glucose is synthesized when blood glucose levels are low and conserved when they are high. Disruptions in glukoneogeneesist can lead to hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar), contributing to various metabolic disorders.