Chapter 15
Principles of Metabolic Regulation:
Glucose and Glycogen
Part 2
Learning Goals: Know
1. How Insulin works to affect genes for gluconeogenesis.
2. How glycogen breakdown works.
3. How liver cells get glycogen converted to glucose not in
the presence of hexokinase. Why?
4. How Glycogen synthesis works beginning with glycogenin.
5. How the Cori cycle works.
6. Regulation of Glycogen synthase and Glycogen
Phosphorylase.
PEP Carboxykinase Regulatory Region is Complex
Glycogen Granules, Liver Cell
Glycogen Phosphorylase
Glycogen Phosphorylase and Debranching Enzyme
Phosphoglucomutase
Liver Transports Glucose to Blood
Not a Cytoplasmic Enzyme
Glycogen Synthase uses UDP-glucose
Synthase
or
Synthetase
There is a
difference!
NDP-sugar Pyrophosphorylase
+ H2O
Glycogen Synthase
Branching Enzyme
Amylo (14) to (16) Transglycosylase
Glycogenin
The Cori’s
Discovered Various Glycogen Diseases
Cori Cycle in Rapid Exercising Muscle and
other ways Muscle becomes Anaerobic
Cori Cycle
Covalent Modification
Discovery of c-AMP
9
Glycogen Phosphorylase Regulation
EOC Problem 6:
Physiological function
of Glycogen
Phosphorylase.
EOC Problem 7:
Looks at
Phosphorylase Eq in
relationship to
regulation.
EOC Problem 8:
More on
Phosphorylase
Regulation.
Phosphorylation Cascade with Ca++ and AMP
Phosphorylase is Also Regulated by Glucose
Allosterically
EOC Problem 10: glycogen breakdown in migrating birds
vs. a fleeing rabbit.
Glycogen Synthase Regulation
Glycogen Synthase Kinase
GSK3 is Phosphorylated to Inactivity
Glycogen Synthase and Phosphorylase Are a
Protein Module
EOC Problem 15 is all
about going from high
blood glucose to low
blood glucose.
Difference Between Liver and Muscle
Things to Know and Do Before Class
1. How Insulin works to affect genes for gluconeogenesis.
2. How glycogen breakdown works.
3. How liver cells get glycogen converted to glucose not in
the presence of hexokinase. Why?
4. Glycogen synthesis beginning with glycogenin.
5. How the Cori cycle works.
6. Regulation of Glycogen synthase and Glycogen
Phosphorylase.
7. EOC Problems 6-8, 10, 15