Energy Storage Flashcards
How and where is glycogen stored?
As granules in the liver and skeletal muscle
What acts as a primer at the core of glycogen?
A dimer of the protein glycogenin
How is glucose converted to glucose-6P?
Phosphorylated by ATP using hexokinase
How is glucose-6P converted to glucose-1P?
The enzyme phosphoglucomutase
Which enzyme catalyses the reaction between glucose-1P and UTP to produce UDP-glucose?
G1P uridylyltransferase
Which enzyme catalyses the reaction between glycogen and UDP-glucose to form a-1-4 bonds?
Glycogen synthase
Which enzyme catalyses the reaction between glycogen and UDP-glucose to form a-1-6 bonds?
Branching enzyme
Which enzymes reacts glycogen with Pi to release a glucose-1P molecule?
Glycogen phosphorylase- a-1-4 bonds
De-branching enzyme- a-1-6 bonds
What is the function of liver glycogen?
A buffer of blood glucose levels
What is the purpose of skeletal muscle glycogen?
To release glucose-6P to be used in glycolysis
Which enzyme converts glucose-6P into glucose in the liver?
Glucose-6-phosphatase
What is the effect of insulin on the activities of glycogen synthase and glycogen phosphorylase?
Glycogen synthase activity increase, glycogen phosphorylase activity decrease
Due to de-phosphorylation of enzymes
What is the effect of glucagon/adrenaline on the activities of glycogen synthase and glycogen phosphorylase?
Glycogen synthase activity decrease, glycogen phosphorylase activity increase
Due to phosphorylation of enzymes
What is the origin of glycogen storage diseases?
They are inherited
What enzyme deficiency causes von Gierke’s disease?
Glucose 6-phosphatase deficiency
