Early in the processing of glucose, a potential futile cycle exist because of the presence of hexokinase (glucokinase in the liver) and glucose-6-phosphatase (only present in liver tissue).
Although the net reaction is the hydrolysis of ATP forming ADP and Pi, this is an important step in liver tissue for whether glucose is committed to specific metabolic pathways (glycolysis, glycogenesis, pentose phosphate pathway) or made available to other tissues in the body.
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