Glycogen Metabolism Flashcards
Incomplete?
where is glycogen stored and synthesised
liver
stored as granules
what is the first step of glycogen synthesis from glucose
conversion to G6P
what enzyme converts G6P to G1P
is it reversible
phosphoglucomutase
yes
what nucleotide is used in glycogen synthesis
what does it form when its used
UTP
UDP-glucose
what protein is used as a start site for a glycogen molecule
glycogenin
what enzyme synthesises glycogen
what is its action
glycogen synthase
remove UDP from UDP glucose and add it to an existing glycogen chain
what type of bind makes the linear bond formation of glycogen
α1-4 bonds
what type of bind makes the branching bond formation of glycogen
α1-6 bonds
the thing abt 7 glucose molecules and glycogen synthase ?
to which end of the chain does glucose get added to glycogen
non-reducing end
steps overview of glycogen synthesis
formation of UDP-glucose
formation of glycogen
UDP glucose reacts with glycogen primer
glycogen synthase
branching enzyme
how long is a given branch of a glycogen primer
12-14 glucose units
which enzyme catalyses glycogenolysis what does it produce
glycogen phosphorylase
glucose 1-phsohate and glycogen (n-1 units)
what happens to G1P in the liver and in muscle
liver: converted to G6P by phosphoglucomutase and then to glucose by glucose 6 phosphate
muscle: there is no glucose 6 phosphate so G6P enters glycolysis
what triggers glycogenolysis during fasting
binding of hormones such as glucagon and epinephrine
also activates protein kinase
