wk 3 - Glycogenesis & Glycogenolysis Flashcards
4?
(fasting)
cAMP
3?
(fasting)
protein kinase
Downstream Metabolic Effects of Insulin increases glucose uptake by most tissues EXCEPT for the ——-
Liver
To synthesise glycogen, glycogen synthase is the active form, whereas, glycogen synthase-P is the inactive form.
a) True
b) False
a) True
- glycogen synthase phosphate must be phosphorylysed (have its phosphate group removed) for it to synthesise glycogen
Glycogen phosphorylase-P acts to degrade glycogen, whereas glycogen synthase acts to synthesise glycogen.
a) True
b) False
a) True
During feeding state, glycogen phosphorylase (dephosphorylated) is in the ______ form.
During feeding state, glycogen phosphorylase (dephosphorylated) is in the inactive form.
In a ________ state, glycogenolytic and lipolytic processes increase.
In a fasting state, glycogenolytic and lipolytic processes increase.
Deficiency of alpha-1,4-glucosidase causes glycogen storage disease ___________
a) Type I
b) Type II
c) Type III
d) Type IV
Deficiency of alpha-1,4-glucosidase causes glycogen storage disease Type II
In ————- state, glycogenic and lipogenic processes increase.
In a feeding state, glycogenic and lipogenic processes increase.
What is the second messenger to be phosphorylated in the insulin’s receptor mechanism of action?
hasnt been identified yet?
Glycogen storage disease type 1a/Von GIerkes disease is caused by _____________ deficiency.
a) Glucose-1-Phosphatase
b) Glucose-6-Phosphatase
c) Translocase T1
d) Translocase T2
Glycogen storage disease type Ia/Von GIerkes disease is caused by Glucose-6-Phosphatase deficiency.
Glycogen storage disease type 1b resulting from deficiency of a specific _______________
a) Glucose-1-Phosphatase
b) Gucose-6-Phosphatase
c) Translocase T1
d) Translocase T2
Glycogen storage disease type Ib resulting from deficiency of a specific Translocase T1
Accumulation of abnormal amounts or types of glycogen in tissues is termed _______________
a) Glycogen abnormality
b) Glycogen storage disease
c) Tissues abnormality
d) Tissues storage disease
b) Glycogen storage disease
During fasting state, which of the following is true:
I. cAMP is active
II. Glycogen phosphorylase-P
III. Glycogen synthase-P
IV. Protein kinase is inactive
a) I, II, IV
b) II, IV
c) I – IV
d) I, II, III
d) I, II, III
1?
(fasting)
glycogen phosphorylase phosphate
(active form of enzyme)
during fasting state, plasma glucose is ______. Thus _________ and ___________ are dominating.
they inactivate ______________ and activate ________________ to breakdown glycogen in order to ________ glucose level in blood
during fasting state, plasma glucose is low. Thus glucagon and epinephrine are dominating.
they inactivate glycogen synthase (to glycogen synthase phosphate) and activate glycogen phosphorylase (to glycogen phosphorylase P) to breakdown glycogen in order to increase glucose level in blood
What is the name of the protein that adds phosphate groups to other proteins?
Kinase
Glycogenolysis is the breakdown of the ———- & ———– linkages in glycogen.
Glycogenolysis is the breakdown of the alpha-1,6 & alpha-1,4 linkages in glycogen.
_________________ & _________________ are the 2 enzymes that makeup the Debranching enzyme complex for glycogenolysis
Glucan transferase & alpha 1-6 glucosidase are the 2 enzymes that makeup the Debranching enzyme complex for glycogenolysis
The enzyme that cleaves glycogen is called ——-
Glycogen phosphorylase-P
hypocalcemia triggers the parathyroid glands to secrete parathyroid hormone (PTH) to reabsorb calcium from bones and reabsorb calcium from kidney. This is a type of ——– stimuli.
hypocalcemia triggers the parathyroid glands to secrete parathyroid hormone (PTH) to reabsorb calcium from bones and reabsorb calcium from kidney. This is a type of humoral stimuli.
name the GLUT protein:
Tissue distribution: Mucosal surface in small intestine, sperm.
Special properties: Primarily fructose carrier in intestine.
GLUT 5
3?
(Fed)
cAMP - decreased by insulin
(cyclic adenosine monophosphate)
A baby with enlarged liver could be the result of:
Glycogen Storage Disease Type IIIB
In the feeding state, insulin stimulates protein —– to activate glycogen synthase to form glycogen.
In the feeding state, insulin stimulates protein Phosphatase-1 to activate glycogen synthase to form glycogen.
During feeding state, plasma glucose is ______, thus _________ is dominating.
it activates _______________ and inactivates ______________ to form glycogen in order to ________ glucose level in the blood and _________ glycogen production
During feeding state, plasma glucose is high, thus insulin is dominating.
it activates glycogen synthase (dephosphorylates glycogen synthase - P) and inactivates glycogen phosphorylase P (phosphorylates glycogen phosphorylase) to form glycogen in order to decrease glucose level in the blood and increase glycogen production
Glycogen storage disease type 1d is deficiency of _________
a) Translocase T1
b) Translocase T2
c) A Transporter that Translocates free glucose molecules
d) A Transporter that Translocate free glycogen molecules
Glycogen storage disease type 1d is deficiency of a Transporter that Translocates free glucose molecules
name the GLUT protein:
Tissue distribution: Neurons, placenta, testes.
Special properties: Low Km (1mM) and high capacity.
GLUT 3
Glycogen Storage Disease type Ia is caused due to a deficiency in ———
Glucose-6-Phosphatase (G6P)
GSD type III/Forbes-Cori disease is also known as or _____________, which affects the liver and skeletal muscles.
Glycogen deposited in these organs has an _________ _________. Differentiating patients with GSD type III from those with GSD type I solely on the basis of physical findings is not easy.
GSD type III/Forbes-Cori disease is also known as or limit dextrinosis, which affects the liver and skeletal muscles.
Glycogen deposited in these organs has an abnormal structure. Differentiating patients with GSD type III from those with GSD type I solely on the basis of physical findings is not easy.
True or false
Glycogen phosphorylase cleaves glucose molecules faster when glycogen is more branched.
True
- alpha 1-6 linkages (branches) can be cleaved by alpha 1-6 glucosidase
In contrast to glycogen storage disease type I, the _____________ are involved in glycogen storage disease type III.
a) Kidney and heart
b) Liver and skeletal muscles
c) Liver and kidney
d) Pancreas and liver
e) Pancreas and skeletal muscles
In contrast to glycogen storage disease type I, the Liver and skeletal muscles are involved in glycogen storage disease type III.
name the GLUT protein:
Tissue distribution: Liver, beta cells, hypothalamus, basolateral membrane small intestine.
Special properties: High capacity but low affinity (high Km, 15-20mM) part of “the glucose sensor” in ß-cells. Carrier for glucose and fructose in liver and intestine!
GLUT 2
GSD type IV, also known as _____________
It is a rare disease that leads to early death.
In 1956, Andersen reported the first patient with progressive hepatosplenomegaly and accumulation of abnormal polysaccharides.
The main clinical features are ______ insufficiency and abnormalities of the heart and nervous system.
GSD type IV, also known as amylopectinosis
It is a rare disease that leads to early death.
In 1956, Andersen reported the first patient with progressive hepatosplenomegaly and accumulation of abnormal polysaccharides.
The main clinical features are liver insufficiency and abnormalities of the heart and nervous system.
Glycogenolysis is the break down of _________ in glycogen.
a) α1→2 branch
b) α1→3 branch
c) α1→4 branch
d) α1→5 branch
e) α1→6 branch
e) α1→6 branch
- cleaving a glycogen branch is done by alpha 1-6 glucosidase
- cleaving individual glucose molecules from this glycogen branch is done by glycogen phosphorylase P, converting them to G6P
One ————– can initiate many cascades of reactions at the same time
One hormone can initiate many cascades of reactions at the same time
2?
(Fed)
protein phosphatase-1
GSD type 0 is when your body synthesises ______ glycogen
GSD type 0 is when your body synthesises zero glycogen
What is the name of the hormone that inhibits insulin and glucagon secretion?
Somatostatin
During a feeding state, plasma glucose is high, thus insulin is high. Insulin works to lower plasma glucose by 2 mechanisms:
- _________ cAMP = _________ glycogen phosphorylase = _________ glycogenolysis
- _________ Protein phosphatase-1 = _________ glycogen synthase = _________ glycogenesis
During a feeding state, plasma glucose is high, thus insulin is high. Insulin works to lower plasma glucose by 2 mechanisms:
- inhibits cAMP = inhibits glycogen phosphorylase = inhibits glycogenolysis
- activates Protein phosphatase-1 = activates glycogen synthase = activates glycogenesis
The more _________ in glycogen, the more glucose molecules are released as an effect of glycogen phosphorylase.
a) α-1,2- linkage
b) α-1,4- linkage
c) α-1,5- linkage
d) α-1,6- linkage
d) α-1,6- linkage
(branched bonds)
For people who have glycogen storage diseases that cause low blood sugar levels, levels are maintained by giving uncooked cornstarch every 4 to 6 hours…
a) Because it increases the glucose level suddenly
b) Because it decreases the glucose level suddenly
c) Because it increases the glucose level gradually
d) Because it decreases the glucose level gradually
For people who have glycogen storage diseases that cause low blood sugar levels, levels are maintained by giving uncooked cornstarch every 4 to 6 hours Because it increases the glucose level gradually
Glycogen storage disease type 1d is deficiency of ________________.
a) Translocase T1
b) Translocase T2
c) A transporter that Translocates free glucose molecules
d) A Transporter that Translocates free glycogen molecules
c) A transporter that Translocates free glucose molecules
For people who have glycogen storage diseases that cause low blood sugar levels, levels are maintained at night by giving them ___________
a) Oral glucose solution
b) Carbohydrate solutions through a stomach tube
c) IV glucose solution
d) IV carbohydrate solution
For people who have glycogen storage diseases that cause low blood sugar levels, levels are maintained at night by giving them Carbohydrate solutions through a stomach tube
2?
(fasting)
phosphorylase kinase phosphate
Diagnosis of glycogen storage disease is via ____________
a) Biopsy
b) Blood samples examination
c) Physical examination
d) X-ray
Diagnosis of glycogen storage disease is via Biopsy
name the GLUT protein:
Tissue distribution: Most cells.
Special properties: High capacity, relatively low Km (1-2mM).
GLUT 1
During fasting state, glucagon and epinephrine ________ cAMP, which ________ protein kinase, which ________ phosphorylase kinase, which ________ the active glycogen phosphorylase phosphate to break down glycogen in order to _______ plasma glucose levels
During fasting state, glucagon and epinephrine increase cAMP, which increases protein kinase, which increases phosphorylase kinase, which increases the active glycogen phosphorylase phosphate to break down glycogen in order to increase plasma glucose levels
Glycogen synthase is essential to synthesise glycogen during fasting state.
a) True
b) False
b) False
- glycogenesis does not occur during fasting state, glycogen synthase would be phosphorylated by protein kinase (inactivated)
In fasting state, glucagon and epinephrine (via protein kinase A) phosphorylate _____________ to inactive it
In fasting state, glucagon and epinephrine (via protein kinase A) phosphorylate glycogen synthase to inactivate it
During fasting state, glycogen phosphorylase should be in the _______ form(glycogen phosphorylase-P) .
During fasting state, glycogen phosphorylase should be in the active form (glycogen phosphorylase-P) .
Glycogenesis happens when there is excess of glucose.
a) True
b) False
a) True
during a fasting state, glucagon and epinephrine work by 2 mechanisms:
- _______ cAMP = _______ protein kinase = ________ phosphorylase kinase = _______ glycogen phosphorylase phosphate = glycogenesis inhibited
- _______ protein kinase = ________ glycogen synthase phosphate = glycogenesis inhibited
during a fasting state, glucagon and epinephrine work by 2 mechanisms:
- increased cAMP = increased protein kinase = increased phosphorylase kinase = increased glycogen phosphorylase phosphate = glycogenesis inhibited
- increased protein kinase = increased glycogen synthase phosphate = glycogenesis inhibited
During fasting state, glycogen phosphorylase should be in the active form, which is ______________
During fasting state, glycogen phosphorylase should be in the active form, which is glycogen phosphorylase phosphate
In contrast to glycogen storage disease type I, ____________ are involved in glycogen storage disease type III.
a) Kidney and heart
b) Liver and skeletal muscles
c) Liver and kidney
d) Pancreas and liver
e) Pancreas and skeletal muscles
b) Liver and skeletal muscles
During fasting state, _________ and ___________ are dominating.
During fasting state, glucagon and epinephrine are dominating.
1?
(Fed)
glycogen synthase
The most common form of glycogen storage disease (GSD) is _________________, which occurs in one out of every 50,000-100,000 births.
The most common form of glycogen storage disease (GSD) is Type 1a, or Von Gierke disease, which occurs in one out of every 50,000-100,000 births.
Glycogen storage disease type Ib is the result of a deficiency in ___________
a) G1Pase
b) G6Pase
c) Translocase T1
d) Translocase T2
Glycogen storage disease type Ib is the result of a deficiency in Translocase T1
In the feeding state, insulin stimulates ______________ to activate glycogen synthase to form glycogen.
In the feeding state, insulin stimulates protein phosphatase-1 to activate glycogen synthase to form glycogen.
Glycogen storage disease type Ia is caused by _________ deficiency.
a) G1Pase
b) G6Pase
c) Translocase T1
d) Translocase T2
Glycogen storage disease type Ia is caused by a G6Pase deficiency.
Glycogen storage disease type 1c is deficiency of _______________
a) G1Pase
b) G6Pase
c) Translocase T1
d) Translocase T2
Glycogen storage disease type 1c is deficiency of Translocase T2
During fasting state, glucagon and epinephrine stimulates _____ to activate _____________ to inactivate/phosphorylate ____________ to glycogen synthase-P so that its action of synthesising glycogen is _________ to ultimately block the ___________ pathway
During fasting state, glucagon and epinephrine stimulates cAMP to activate protein kinase A to inactivate/phosphorylate glycogen synthase to glycogen synthase-P so that its action of synthesising glycogen is inhibited to ultimately block the glycogenesis pathway
Glycogen storage disease type 1c is deficiency of __________
a) G1Pase
b) G6Pase
c) Translocase T1
d) Translocase T2
Glycogen storage disease type 1c is deficiency of Translocase T2
The glucose transporter in case of muscle is ————–.
a) GLUT-2
b) GLUT-3
c) GLUT-4
d) GLUT-5
c) GLUT-4
4?
(Fed)
glycogen phosphorylase
(inactive form of enzyme)
Glucose molecules are bound together to form glycogen. In the same chain, they are linked via α-1,4- linkage, whereas branched chains are linked via:
a) α-1,2- linkage
b) α-1,3- linkage
c) α-1,5- linkage
d) α-1,6- linkage
d) α-1,6- linkage
During feeding state, glycogen synthase should be in the active form, which is:
a) Glycogen synthase
b) Glycogen synthase-P
a) Glycogen synthase
An essential pathologic finding in Glycogen storage disease ___________________ is the accumulation of normally structured glycogen in most tissues
An essential pathologic finding in Glycogen storage disease type II/ Pompe disease is the accumulation of normally structured glycogen in most tissues
An essential pathologic finding in Glycogen storage disease type _____________ disease is the accumulation of normally structured glycogen in most tissues
An essential pathologic finding in Glycogen storage disease type Type II/Pompe disease is the accumulation of normally structured glycogen in most tissues
During feeding state, glycogen phosphorylase should be in the inactive form ____________ to avoid glycogen breakdown.
a) Glycogen synthase
b) Glycogen synthase-P
c) Glycogen phosphorylase-P
d) Glycogen phosphorylase
d) Glycogen phosphorylase
The glucose transporter in case of liver is ————–.
a) GLUT-2
b) GLUT-3
c) GLUT-4
d) GLUT-5
a) GLUT-2
Deficiency of alpha-1,4-glucosidase causes glycogen storage disease of _____________
a) Type I
b) Type II
c) Type III
d) Type IV
Deficiency of alpha-1,4-glucosidase causes glycogen storage disease of Type II
The most common forms of GSD are types __ to __ & __.
The most common form form is type __
The most common forms of GSD are types 1 to 5 & 9.
The most common form form is type 1a - Von Gierke disease
During fasting state, glycogen synthase should be in the inactive form, which is _______________
During fasting state, glycogen synthase should be in the inactive form, which is glycogen synthase phosphate
All of the following enzymes act during glycogen degradation EXCEPT:
a) Alpha-1,6-glucosidase
b) Glucan transferase
c) Glycogen phosphorylase-P
d) Glycogen synthase
d) Glycogen synthase
- used in glycogenesis
the order of enzymes involved in glycogenolysis are:
- Glycogen phosphorylase-P
- Glucan transferase
- Alpha-1,6-glucosidase
Diagnosis of glycogen storage disease is caried out prior to birth/prenatal via _________________
Diagnosis of glycogen storage disease is caried out prior to birth/prenatal via chorionic villi sampling and amniocentesis
chorionic - pertaining to the chorion. chorionic villi numerous branching projections from the external surface of the chorion that provide for exchange between the maternal and fetal circulation. Oxygen and nutrients in the maternal blood diffuse through the walls of the villi and enter the blood of the embryo or fetus.
Amniocentesis - (also referred to as amniotic fluid test) is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, and also for sex determination, in which a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amniotic sac surrounding a developing fetus, and then the fetal DNA is examined for genetic abnormalities.
Glycogen is stored in:
a) Kidney and muscle
b) Liver and muscle
c) Muscle and pancreas
d) Pancreas and liver
b) Liver and muscle
Removal of a terminal glucose residue from the non reducing end of a glycogen chain is done by _____________
a) Glycogen hydrolase
b) Glycogen phosphorylase-P
c) Glycogen synthase
d) Glycogen synthase-P
b) Glycogen phosphorylase-P
- alpha 1-4 glycosidic bonds only, alpha 1-6 glycosidase cleaves the alpha 1-6 bonds
During feeding state, glycogen phosphorylase should be in the ________ state.
During feeding state, glycogen phosphorylase should be in the inactive state.
5?
(fasting)
glycogen synthase phosphate
(inactive form of enzyme)
Liver doesn’t contain the insulin sensitive transporter ——–
a) GLUT 1
b) GLUT 2
c) GLUT 3
d) GLUT 4
e) GLUT 5
d) GLUT 4
During feeding state, plasma glucose is high, thus insulin is dominating.
It increases _________________, which activates _____________ to form glycogen in order to _______ plasma glucose levels
During feeding state, plasma glucose is high, thus insulin is dominating.
It increases protein phosphatase-1, which activates glycogen synthase to form glycogen in order to decrease plasma glucose levels
name the GLUT protein:
Tissue distribution: Skeletal and cardiac muscle, fat.
Special properties: Activated by insulin. Km 5mM.
GLUT 4
Some types of glycogen storage disease can be detected even before __________ occurs, if both parents are tested for the presence of the defective gene.
Some types of glycogen storage disease can be detected even before conception occurs, if both parents are tested for the presence of the defective gene.
During feeding state, glycogen synthase should be in the _______ state.
During feeding state, glycogen synthase should be in the active state.
During fasting state, glycogen synthase should be in the _______ state.
During fasting state, glycogen synthase should be in the inactive state.
