Glucose 1-phosphate glycogen, conversion

In the previous section we considered three possible pathways for glucose-6-phosphate dephosphorylation by glucose-6-phosphatase, conversion to fructose-6-phosphate followed by oxidation through the Embden-Meyerhof pathway, and conversion to glucose-1-phosphate followed by glycogen synthesis. A fourth pathway exists—the hexose monophosphate shunt [61-63]. 

Figure 22.17 Summary of mechanisms to maintain the ATP/ADP concentration ratio in hypoxic myocardium. A decrease in the ATP/ADP concentration ratio increases the concentrations of AMP and phosphate, which stimulate conversion of glycogen/ glucose to lactic acid and hence ATP generation from glycolysis. The changes also increase the activity of AMP deaminase, which increases the formation and hence the concentration of adenosine. The latter has two major effects, (i) It relaxes smooth muscle in the arterioles, which results in vasodilation that provides more oxygen for aerobic ATP generation (oxidative phosphorylation). (ii) It results in decreased work by the heart (i.e. decrease in contractile activity), (mechanisms given in the text) which decreases ATP utilisation.

A metabolite, molecular entity, or some other event/ process that precedes another component in a longer sequence of events or conversions. For example, the isoprenoid metabolite squalene is a precursor of cholesterol and glucose 6-phosphate is a precursor of glycogen, ribose, and pyruvate. See Series First Order Reaction Pulse-Chase Experiments... 

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