Glycogen Synthesis, Degradation, and Related Diseases Flashcards
Insulin activates ________ which activates ________ and deactivates ________ through dephosphorylation.
Activated ________ then makes glucagon
Insulin activates protein phosphatase which activates glycogen synthase and deactivates glycogen phosphorylase through dephosphorylation.
Activated glycogen synthase then makes glucagon
Glucagon activates ________ which activates ________ and deactivates ________ through phosphorylation
Activated ________ then leads to the conversion glycogen to glucose
Glucagon activates protein kinase which activates glyogen phosphorylase and deactivates glycogen synthase through phosphorylation
Activated glycogen phosphorylase then converts glycogen to glucose
During musle contractions, Ca2+ is releasedd from the sacroplasmic reticulum. Ca2+ binds to and activates ________, which then activates glycogen phosphrylase causing glycogen degradation
In muscle under extreme conditions of anoxia and depletion of ATP, ____ activates glycogen phosphorylase
During musle contractions, Ca2+ is releasedd from the sacroplasmic reticulum. Ca2+ binds to and activates phosphorylase kinase, which then activates glycogen phosphrylase causing glycogen degradation
In muscle under extreme conditions of anoxia and depletion of ATP, AMP activates glycogen phosphorylase
The primary dietary approach to treating glycogen storage disorders is frequent feeding, increasing the proportion of ____ in the diet, and giving ____ during prolonged fasting such as overnight
The primary dietary approach to treating glycogen storage disorders is frequent feeding, increasing the proportion of carbohydrates in the diet, and giving cornstarch during prolonged fasting such as overnight
Type 1 Glycogen Storage Disease is also called?
von Gierke
Type I Glycogen Storage Disease (also called ____)
- Deficiency of ____; liver cannot release free glucose in response to low blood sugar
- Excess ____ funneled back into glycolysis, results in
- Elevated ____ (____ acidemia)
- Excess ____ stored; ____ structure
- Treatment involves ____________
- Phenotyp/labs (6 examples):
Type I Glycogen Storage Disease (also called von Gierke)
- Deficiency of glucose-6-phosphatase ; liver cannot release free glucose in response to low blood sugar
- Excess glucose-6-phosphate funneled back into glycolysis, results in
- Elevated lactate (lactic acidemia)
- Excess glycogen stored; normal structure
- Treatment involves frequent feedings; cornstarch (releases glucose slowly)
- Phenotype/labs:
- Enlarged liver and kidneys
- Growth failure
- Hypoglycemia
- Lactic acidemia
- Hyperuricemia
- Elevated AST/ALT
Type VI Glycogen Storage Disease (Also called ________)
- Defective ________ (unable to effectively break down glycogen)
- Increased levels of ____; ____ structure
- ____ is infrequent and mild; relies on gluconeogenesis
- Phenotype/Labs (2 examples):
Type VI Glycogen Storage Disease (Also called Hers_’ Disease_)
- Defective liver glycogen phosphorylase (unable to effectively break down glycogen)
- Increased levels of glycogen; normal structure
- Hypoglycemia is infrequent and mild; relies on gluconeogenesis
- Phenotype/Labs:
- Hepatomegaly
- Hypoglycemia (infrequent/mild)
Glycogen Storage Diseases (GSDs) I - VI follow which type of genetic inheritance?
They are autosomal recessive
When a GSD is related to a enzyme defect in the liver, ____ usually results due to impaired glucose mobilization for release during fasting
When a GSD is related to a enzyme defect in the liver, hypoglycemia usually results due to impaired glucose mobilization for release during fasting
When a GSD is related to an enzyme defect in muscle, ____ and ________ results from an inability to increase glucose entry into glycolysis during exercise
When a GSD is related to an enzyme defect in muscle, weakness and difficulty exercising results from an inability to increase glucose entry into glycolysis during exercise
Type V Glycogen Storage Disease (Also called ________)
- Defective: ________ (unable to break down muscle glycogen)
- Elevated levels of muscle ____ with ____ structure
- Phenotype/Labs (5 examples):
Type V Glycogen Storage Disease (Also called McArdle disease)
- Defective: Muscle glycogen phosphorylase (unable to break down muscle glycogen)
- Elevated levels of muscle glucose with normal structure
- Phenotype/Labs (4 examples):
- Exercise induced muscle pain
- Rhabdomyolysis (break down of muscle to provide energy, releases creatine kinase and myoglobin into the blood)
- Myoglobinuria (red urine due to high protein concentration)
- Reduced lactate output
- Premature fatigue/cramps/progressive weakness
What glycogen storage disease is also a lysosomal storage disease?
What organs is this predominant in?
Type II Glycogen Storage Disease (Pompe’s Disease)
All organs with lysosomes but is predominant in the heart, skeletal muscles, and CNS
Type II Glycogen Storage Disease (Also called ________)
- Defect: ________
- Also a ____ disease
- Massive increase in ____ in all organs; ____ structure
- Phenotype/Labs (4 exxamples):
Type II Glycogen Storage Disease (Also called Pompe’s Disease)
- Defect: Lysosomal a-glucosidase (excessive glycogen in abnormal vacuoles in lysosomes)
- Also a lysosome disease
- Massive increase in glycogen in all organs; normal structure
- Phenotype/Labs:
- Huge heart (infants)
- Enlarged tongues
- Weakness
- Often leads to an early death
Type III Glycogen Storage Disease (Also called ________)
- Defect: ________
- Effected organs: ____ and ____
- Increased amounts of ____; ____ structure
- Pheontype/Labs (3 examples):
Type III Glycogen Storage Disease (Also called Cori’s Disease)
- Defect: Debranching enzymes
- Effected organs: Liver and Muscle
- Increased amounts of glycogen; short branches glycogen structure
- Pheontype/Labs:
- Fasting hypoglycemia
- Hypertrophic cardiomyopathy (thicking of heart muscle)
- Hepatomegaly
Type IV Glycogen Storage Disease (Also called ________)
- Defect: ________
- ____ amount of glycogen; ____ structure
- Phenotype/Labs:
Type IV Glycogen Storage Disease (Also called Andersen’s Disease)
- Defect: Branching Enzyme
- Normal amount of glycogen; abnormally long, relatively straight glucose polymers
- No ____
- Phenotype/Labs:
- Hepatomegaly
- Muscle atrophy
- Progressive liver cirrhosis
- Hypertonia
