Hexose monophosphate pool

The hexose monophosphate pool. The equilibrium percentages of the three hexose monophosphates are indicated. Horizontal flow arrows indicate major routes of replenishment and utilization of the three hexose monophosphates. 

When fructose-6-phosphate is generated by gluconeogenesis or photosynthesis (see chapter 15), an equimolar amount of glucose-1-phosphate is usually removed from the hexose monophosphate pool by conversion to storage polysaccharide (glycogen in animals and many kinds of microorganisms starch in green plants). 

We will focus our discussion on the well-understood regulatory enzymes that modulate the flux between glycogen and the hexose monophosphate pool (pseudocycle la), and between fructose-6-phosphate and fructose-1,6-bisphosphate (pseudocycle II). Some aspects of the regulation between the 3-carbon pool and pyruvate (pseudocycle III) are discussed in the next chapter. 

Glycolysis and gluconeogenesis proceed through three pools of intermediates that are close to equilibrium. The pools are the hexose monophosphate pool, the aldolase pool, and the three-carbon pool. 

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