Glükózképzéshez

Glükózképzéshez, or gluconeogenesis in English, is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. This process is crucial for maintaining blood glucose levels, especially during periods of fasting or starvation, when dietary intake of carbohydrates is insufficient. It is also important for providing glucose to tissues that rely heavily on it as their primary energy source, such as the brain and red blood cells.

The primary sites for gluconeogenesis in mammals are the liver and, to a lesser extent, the kidneys. The substrates for gluconeogenesis include pyruvate, lactate, glycerol, and certain amino acids. These molecules are converted into glucose through a series of enzymatic reactions. While many of the reactions are reversible steps of glycolysis, three key irreversible steps of glycolysis are bypassed by distinct enzymes in gluconeogenesis. These are the conversion of pyruvate to phosphoenolpyruvate, fructose-1,6-bisphosphate to fructose-6-phosphate, and glucose-6-phosphate to glucose.

Hormonal regulation plays a significant role in controlling gluconeogenesis. Glucagon, released when blood glucose is low, promotes gluconeogenesis. Conversely, insulin, released when blood glucose is high, inhibits this process. Dysregulation of gluconeogenesis can contribute to conditions like diabetes mellitus, where persistently high blood glucose levels can occur. Understanding gluconeogenesis is fundamental to comprehending carbohydrate metabolism and its implications for overall health.