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 paradox small absorption of glucose. After the body's digestion of carbohydrates and the entering the circulatory system in the form of glucose, some will be absorbed directly into the muscle tissue and will be converted into lactic acid throughout the anaerobic energy system, rather than going directly to the liver and being converted into glycogen. The lactic acid is then taken and converted by the liver, forming the material for liver glycogen. The majority of the body's liver glycogen is produced indirectly, rather than directly from glucose in the blood. Under normal physiological conditions, glucose is a poor precursor compound and