In the regulation of glycogen phosphorylase, explain the roles
of phosphodiesterase, GTPase of the alpha subunit...
In the regulation of glycogen phosphorylase, explain the roles
of phosphodiesterase, GTPase of the alpha subunit of the G protein,
and G-protein coupled receptor systems.
Regulation of Glycogen Metabolism (McKee page
317-323)
Compare activities of glycogen phosphorylase and
glycogen synthase based on storing glucose energy in a
cell
Describe the stimulus for the pancreas to release
glucagon based on blood glucose concentration
Describe the target for the glucagon signal based on
the cell type that has receptors for glucagon
Describe the activity of glycogen phosphorylase based
on glucagon stimulation of the cell
Describe the activity of glycogen synthase based on
glucagon stimulation of the cell...
3. Glycogen Degradation
a) What are the steps in the breakdown of glycogen?
b) Glycogen phosphorylase exists in different forms and
conformations under different physiological conditions. In a
resting muscle, MOST of the phosphorylase will be
in which form and which state?
c) How do hormones regulate glycogen breakdown?
The nucleophile that is used to free most glucose from glycogen
is__________, and Glycogen phosphorylase is active when it is
_________________.
1. ATP
2. Tyrosine
3. Serine
4. Inorganic phosphate
5. Water
6. Hydroxide
A. Phosphorylated
B. Not phosphorylated.
C. Denatured.
Outline the unique hormonal regulation for glycogen degradation
in liver and muscle. Also, include the roles of insulin, glucagon,
and Epinephrine in your answer. (Flow chart is acceptable)
Outline the unique hormonal regulation for glycogen degradation
in liver and muscle. Also, include the roles of insulin, glucagon,
and Epinephrine in your answer. (Flow chart is acceptable)
Outline the unique hormonal regulation for glycogen degradation
in liver and muscle. Also, include the roles of insulin, glucagon,
and Epinephrine in your answer. (Flow chart is acceptable)
The alpha-s subunit of G proteins will be activated
when __________.
A) the alpha s-subunit binds to GTP
B) the alpha s-subunit is complexed with the G protein
beta and gamma subunits
C) the alpha s-subunit is translocated into the
nucleus
D) the alpha s-subunit is phosphorylated
1. Describe the function of the following enzymes: glycogen
phosphorylase, glycogen synthase, protein kinase a, adenylate
kinase, branching enzyme
2. a. Why do cell extracts require NAD+ to convert
glucose to pyruvate? What intermediates accumulate when
NAD+ is absent? Explain. b.Why does the rate at which
glucose is converted to pyruvate decrease when citrate is
added?
3. Define gluconeogenesis. What molecules are good substrates
for gluconeogenesis? Biosynthetic and catabolic pathways are rarely
identical. Is this true for gluconeogenesis vs. glycolysis?...
. Explain how glycogen phosphorylase is regulated by AMP, ATP,
G6Pand phosphorylation/dephosphorylation? What is the physiological
significance of these control mechanisms? b. What are the effects
of the following on the rates of glycogen synthesis and
degradation? (a) increasing the Ca2+ ion concentration, (b)
increasing the ATP concentration, (c) inhibiting adenylate cyclase,
(d) increasing the epinephrine concentration, (e) increasing the
AMP concentration. Explain.