CLINICAL CASES

2 3

Glycogen Phosphorylase

GLYCOGENESIS

Slycogen Synthase

G lycogen

Blood

UDP

(n residue«)

UDP G lucose

Glucose

UTP

Glycogen

Glucose 1-P

G lucose 6-P

J fo

(n+1 re s id u e s

G lycolysis

G lycogen

Energy

n residues)

GLYCOGENOLYSIS

Figure 26-2. The biochemical pathways of the synthesis of glycogen (glyco-

genesis) and its breakdown to glucose 6-phosphate (glycogenolysis).

acetyl-CoA is shunted into the pathway of ketone body synthesis (ketogenesis),

allowing continued P-oxidation of fatty acids and therefore maintenance of

high rates of gluconeogenesis. The interplay between glycolysis, gluconeogen-

esis, P-oxidation, and ketogenesis is illustrated in Figure 26-3.

Figure 26-3. Schematic diagram of the interplay of fatty acid breakdown and

ketone body formation with the synthesis (gluconeogenesis) and degradation

of glucose (glycolysis). The P-oxidation of fatty acids provides the energy that

drives the formation of glucose.