glükóz6foszfáttá
Glükóz6foszfát (G6P), also known as glucose-6-phosphate, is a molecule that plays a crucial role in cellular metabolism. It is formed when glucose is phosphorylated by the enzyme hexokinase or glucokinase. This phosphorylation is the first step in glycolysis, the primary pathway for glucose breakdown to produce energy. G6P is an intermediate in many metabolic pathways, including glycolysis, gluconeogenesis, the pentose phosphate pathway, and glycogen synthesis and breakdown. Its formation traps glucose within the cell, as the phosphate group prevents it from easily crossing the cell membrane. In the pentose phosphate pathway, G6P is converted to NADPH, a reducing agent vital for various cellular processes, and precursors for nucleotide synthesis. In glycogen synthesis, G6P is converted to glucose-1-phosphate, which is then used to build glycogen stores. Conversely, during glycogenolysis, glycogen is broken down to glucose-1-phosphate, then converted to G6P, and finally dephosphorylated to glucose for release into the bloodstream or further metabolism. Deficiencies in the enzyme glucose-6-phosphatase, which converts G6P back to glucose, can lead to glycogen storage diseases, affecting the liver's ability to release glucose.