Glycogen degradation exam 2 Flashcards
Glucose sources?
Diet glycogen gluconeogenesis
Glucose’s energy source for?
Brain
Blood cells
Exercising muscles
Gluconeogenesis
Synthesis of glucose
Slow response
Glycogen and low blood sugar
Glycogen in liver and kidney can breakdown and release glucose quickly
Glycogen and exercising muscle
Glycogen in muscle can breakdown and release glucose for energy
Glycogen primary sites for storage
Liver and skeletal muscle
Chains of glucose are connected by what glycosidic bonds?
A (1-4)
Branch points are formed by what glycosidic bonds
A(1-6)
Occurs every 10 glucose molecules
Increased solubility
Easier access to glucose
Where is glycogen stored
Cytosol
Glycogen to glucose 1 phosphate what enzyme and coenzyme is used
Glycogen phosphorylase and pyridoxal phosphate
Mutation phase
Glucose 1 phosphate converted to glucose 6 phosphate by phosphoglucomutase
T/F muscles lack the enzyme needed to release glucose
True
Glucose 6 phosphate and the liver
Converted to free glucose (g6p)
ER
Glucose sent to cytosol (released in the blood stream)
G6P and the muscles
Glycolysis
Is phosphorylase still effective at breaking down glycogen?
No
How many glucose molecules have to be left in order for glycogen breaking down to stop proceeding?
4
What are the enzymes required in order to break down the branches?
Glucosyl (4:4) transferase removes 3 outer glucose molecules Amylo a(1 6) glucosidase removed the last glucose branch
When does glycogen phosphorylase begin again
After it gets four away from the last branch
Glycogenolysis regulation main enzyme?
Glycogen phosphorylase
Glycogenolysis regulation in the liver is
Fasting stimulating
Glycogenolysis in the muscle is
Stimulated during exercise
Glycogenolysis regulation and hormones
Glucagon (liver)
Epinephrine (liver muscle)
Activation of adenylyl cyclase
Camp
Protein kinase a PKA
Glycogen regulation is broken down by what
Calcium (muscle contraction) Epinephrine Low energy charge Low blood glucose (glucagon) ADP AMP
Calcium is released where and binds to what
Released in muscle (neural stimulation) and liver (epinephrine)
Binds to calmodulin (caM) Ca2+-CaM complex
What does calmodulin activate
Phosphorylase kinase
Ca+ and energy charge
Muscle contraction uses ATP
Neural stimulation releases Ca2+ from SR. (which binds to CaM)
Ca2+ and stress
Liver
Epinephrine released from adrenal medulla (need glucose)
Releases Ca2+ from ER to cytoplasm and binds to CaM
AMP and energy charge
Muscle
High levels of AMP
AMP binds to glycogen phosphorylase b (no phosphorylation)
Glycogen phosphorylase
Low ATP High levels of ADP AMP Low levels of glucose Glucagon (liver) Muscle contraction (calcium)
Glycogen synthase
Lots of ATP
High levels of glucose
Insulin
Low glucagon levels
Enzymes for glycogen breakdown
Glycogen phosphorylase Phosphoglucomutase Glycosyl (4:4) transferase Amylo a (1 6) glucosidase Glucose 6 phosphate
