Glucose cycle The glucose cycle can occur in liver cells due to a liver specific enzyme glucose-6-phosphatase, which catalyse the dephosphorylation of glucose 6-phosphate back to glucose. Glucose-6-phosphate is the product of glycogenolysis or gluconeogenesis, where the goal is to increase free glucose in the blood due body being in catabolic state. Other cells such as muscle and brain cells do not contain glucose 6-phosphatase. As a result, any glucose 6-phosphate produced in those cells is committed to cellular metabolic pathways, primarily pentose phosphate pathway or glycolysis. Flux through the glucose cycle is regulated by several hormones including insulin and glucagon as
Glucose 6-phosphate this enzyme, so myofibers use glucose-6-phosphate in their own metabolic pathways such as glycolysis. Importantly, this prevents myocytes from releasing glycogen stores they have obtained into the blood. Glucose 6-phosphate Glucose 6-phosphate (sometimes called the Robison ester) is a glucose sugar phosphorylated at the hydroxy group on carbon 6. This dianion is very common in cells as the majority of glucose entering a cell will become phosphorylated in this way. Because of its prominent position in cellular chemistry, glucose 6-phosphate has many possible fates within the cell. It lies at the start of two major metabolic pathways: glycolysis and the