Glucose 1-phosphate glycogen degradation

In muscle, all the glucose 6-phosphate arising from glycogen degradation (via glucose 1-phosphate) either goes down glycolysis or enters the HMP pathway. 

During glycogen degradation in muscle, the main aim is to produce energy quickly and so the glucose 6-phosphate is metabolized immediately via glycolysis. This tissue does not contain glucose 6-phosphatase. 

Figure 18.12 Glycogen degradation. P, indicates inorganic phosphate. Designation of glucose molecules as in Figure 18.11.

Glycogen degradation produces glucose 1-phosphate as the major product, but free glucose is also formed. 

Glycogen is degraded (glycogenolysis) by phosphorylase to form glucose phosphates. 

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