Glucose Metabolism Flashcards
Forms UDP-glucose from glu-1-P and UTP
UDP-glucose pyrophosphorylase
Removes the glucose units from a non-reducing end of glycogen
Glycogen phosphorylase
What cofactor does glycogen phosphorylase require?
(pyridoxal phosphate)
Role of insulin on glycogen metabolism
Stimulates glycogenesis, inhibits glycogenolysis in liver and muscle
Role of glucagon on glycogen metabolism
Inhibits glycogenesis, stimulates glycogenolysis in liver via increases in cAMP in liver cells
Role of epinephrine on glycogen metabolism
Stimulates glycogenolysis in liver and muscle via increases in cAMP in both, increasing Ca+ in liver cells
Acitve form of glycogen phosphorylase
phosphorylase-a
Controls the activation/inactivation of glycogen phosphorylase
Phosphorylase kinase
Activates phosphorylase kinase
Ca+, phosphorylation
How is epinephrine’s effect different in the liver and muscle?
Liver: increased cAMP inhibits glycolysis and stimulates gluconeogenesis. Muscle: increased cAMP stimulates glycolysis
Define glucogen storage diseases
Inherited disorders that are characterized by deposition of an abnormal type or quanity of glycogen in tissues OR failure to mobilize glycogen
GSD0a
Affects glycogen synthase-2 (liver). S&S: hypoglycemia, early death, hyperketonia, low blood lactate/alanine
Cori or Forbes disease
Affects liver and muscle debranching enzyme. (Liver, skeletal and cardiac muscle). S&S: infant hepatomegaly, myopathy
Andersen disease
Affects branching enzyme. (Liver and muscle). Heptosplenomegaly, cirrhosis, Exercise enduced.
McArdle disease
Muscle phosphorylase. (Skeletal Muscle). Cramps, pain, myoglobinuria, hepatomegaly, mild mypoglycemia
