Glycogen Flashcards
(29 cards)
Glycogen is most abundant in muscle and liver.
True
Glycogen is a storage form of glucose.
True
Polymer of glucose.
Glycogen phosphorylase removes glucose from glycogen polymer.
True
Enzyme that breakdown Glycogen?
Glycogen Phosphorylase
What is the influence of Glucagon and Epinephrine at Glycogen?
They favor the breakdown of glycogen in glucose.
Insuline - High blood sugar
Favors synthesys of glycogen from glucose.
Is there a way to glycogen breakdown in the absence of hormones?
MUSCLE CONTRACTION
Calcium/calmodulin activate GP Kinase A which will phosphorylate glycogen phosohorylase - glycogen breakdown;
High ATP (WORD) Glycogen Phosphorylase
Inhibits
Glucose 6-P (word) Glycogen synthase
Stimulates
AMP (WORD) Glycogen Phosphorylase
Stimulates
Charactheristics of glycogen storage diseases:
Most autosomal recessive;
Defective breakdown of glycogen;
Liver: hypoglycemia;
Muscle: Weakness;
More than 14 described.
Pompe’s Disease other name:
Glycogen Storage Disease type II
Acid alpha-glucosidase deficiency is also known as…
Pompe Disease
Accumulation of glycogen in lysosomes
Pompe’s Disease signals:
Enlarged Muscles
- Cardiomegaly;
- Enlarged tongue;
Hypotonia
Liver enlargement;
No hypoglycemia;
Death from heart failure
Fasting hypoglycemia with ketosis causing weakness and lethargy in the morning is???
Glycogen Synthase deficiency
FASTING HYPOGLYCEMIA + POST PRANDIAL HYPERGLYCEMIA REPRESENTS DEFICIENCY OF WHICH ENZYME?
Glycogen Synthase deficiency
Fasting hypoglycemia occurs in GSDIII because the liver is ineffective at producing glucose from glycogen in absence of the debranching enzyme.
TRUE
Cori disease
Glycogen Storage Disease type III
Glycogen storage disease type I (GSDI; von Gierke disease) is caused by a deficiency of the enzyme glucose-6-phosphatase. As a result, the liver cannot metabolize glycogen into glucose. Glycogen accumulates in the liver causing hepatomegaly. Fasting hypoglycemia with ketosis and lactic acidosis occurs due to inability to breakdown glycogen in the fasting state.
Vongierke Disease
To achieve these goals, frequent small meals are advised. Patients with GSDI often have to wake during the night to eat, one of many difficulties in living with the disorder. Foods containing complex carbohydrates are also recommended. These are slowly absorbed and metabolized into glucose allowing for longer periods of time between meals. Cornstarch is a mainstay of therapy for this reason (high-yield fact!). Other starch-containing foods like potatoes or rice are also recommended.
The alanine cycle converts the amino acid alanine into glucose in the liver. This is disrupted in GSDI and, therefore, elevated serum alanine levels occur.
TRUE
Glycogen Storage Disease type I
VOn Gierke disease
Myophosphorylase deficiency (McArdle disease) is a disorder, that myocytes cannot break down glycogen which leads to exercise intolerance, myalgias, and weakness. Muscle damage with exercise (rhabdomyolysis) may occur leading to myoglobinuria, dark urine, and an elevated creatine kinase level.
True
Von Gierke’s Disease has deficiency of which enzyme?
Glucose 6 phosphatase deficiency
Von Gierkes Disease signals:
Severe hypoglycemia between meals;
Lethargy, Seizures, Lactic acidosis;
Enlarged liver (excesses of glycogen);
Treatment of Von Gierkes Disease:
Cornstarch + avoid sucrose lactose, fructose, galactose;
Cori’s disease also known as…
Glycogen Diseas Type III
