Deck 25: Glycogen Synthesis

Question 1

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
The reaction catalyzed by __________________ transfers UDP-glucose to the hydroxyl of an existing glycogen core.

Answer 1

glycogen synthase

Question 2

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
_______________ is the key regulatory enzyme in glycogen synthesis.

Answer 2

g

Question 3

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
The protein _______________ serves as the primer used by glycogen synthase.

Answer 3

e

Question 4

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
_______________ is the activated form of glucose that is required for glycogen synthesis.

Question 5

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
__________________ is is a primer that polymerizes the first few glucose molecules.

Question 6

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
Hydrolysis of _______________ drives the formation of UDP-glucose.

Question 7

In general, phospho- forms of glycogen synthase lead to ________________ levels of glycogen.

Question 8

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
__________________ acts as a "high-energy handle" for biosynthetic reactions, including glygogen synthesis.

Question 9

Glycogen synthase catalyzes the transfer of a glucose residue from UDP-glucose to one of the __________________ ends of glycogen.

Question 10

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
Synthesis of glycogen starts with the phosphate group transfer from UTP to _______________.

Question 11

The complete oxidation of a glucose residue from glycogen produces ________________ ATP.

Question 12

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
Glucosyl units are added to the _______________ end, or terminal, of glycogen.

Question 13

Insulin stimulates glycogen synthase by inactivating __________________.

Question 14

Glycogen synthase is converted into the active form by the action of __________________.

Question 15

The glycogen branching enzyme moves a block of __________________ (or so) glucose residues to from a branch point at least four residues from a preexisting branch.

Question 16

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
_______________ dissociates from phosphorylase a in the T state.

Question 17

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
Glycogen _______________ is inhibited by phosphorylase kinase.

Question 18

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
_______________ is the storage disease in which light exercise results in cramps.

Question 19

There is a high __________________-to-insulin ratio in diabetes.

Question 20

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) UDP-glucose
b) nonreducing
c) synthesis
d) glucose
e) glycogenin
f) Von Gierke disease
g) glycogen synthase
h) UTP-glucose
i) protein phosphatase 1 (PP1)
j) PPi
k) glycogen phosphate
l) McArdle disease
_______________ is the glycogen storage disease in which the defective enzyme is glucose 6-phosphatase.

Question 21

Glycogenin:

A) consists of dimmer proteins.
B) self-assembles eight glycosyl units.
C) is the primer for glycogen synthase.
D) B and C.
E) All of the above.

Question 22

The enzyme that begins the kinase cascade, activating glycogen degradation, is:

A) glycogen synthase.
B) phosphorylase kinase.
C) PKC.
D) PKA.
E) tyrosine kinase.

Question 23

Type I diabetes leads to ______________ in the liver.

A) increased glucose transport
B) increased glycogen synthesis
C) a decrease in fructose 2,6-phosphate
D) a decrease in gluconeogenesis
E) All of the above.

Question 24

Explain how the liver responds to muscle challenges in insulin-dependent diabetes.

Question 25

______________ results from a loss or inactivation of insulin receptors.

A) Hypoglycemia
B) Hyperinsulinemia
C) Type I diabetes
D) Type II diabetes
E) None of the above.

Question 26

The __________________ creates a 1,6-glycosidic bond.

A) branching enzyme
B) glucose transferase
C) glycogen isomerase
D) glycogen synthase
E) None of the above.

Question 27

Which of the following occur after a carbohydrate-rich meal?

A) Blood-glucose levels increase, leading to glycogen storage in the liver.
B) Blood-glucose levels increase, leading to glycogen storage in the muscle.
C) Glycogen storage in the muscle shuts down.
D) All of the above.
E) None of the above.

Question 28

Explain why Type I diabetes is often called "fasting in the sea of plenty."

Question 29

Which is the true glucose-level sensor in the cell?

A) insulin
B) phosphorylase a
C) glucagon
D) glycogen synthase
E) protein phosphatase 1

Question 30

How are new glucosyl units added to a growing glycogen molecule?

Question 31

The activated glucose donor of glycogen synthesis is:

A) glucose 1-phosphate.
B) glucose.
C) ATP.
D) UTP.
E) None of the above.

Question 32

Using thermodynamic terms, describe the mechanism by which UDP-glucose is formed.

Question 33

There is rare disease in which a critical serine in muscle glycogenin is mutated to alanine, which results in what biochemical outcome?

Question 34

Which enzyme(s) is/are required to synthesize ɑ-1,4-glycosidic bonds in glycogen?

A) glycogen synthase
B) UDP-glucose phosphorylase
C) branching enzyme
D) A and B
E) B and C

Question 35

An incorrect, tight binding of PP1 to glycogen synthase would result in:

A) a hyperactive glycogen synthase.
B) hyper-glycogen levels.
C) increased insulin action.
D) high blood glucose.
E) activated glycogen synthase.

Question 36

After exercise, muscle cell glycogen metabolism is regulated by:

A) insulin.
B) phosphorylase a.
C) glucagon.
D) glycogen synthase.
E) protein phosphatase 1.

Question 37

Explain the conversion between both a and b, and R and T forms of phosphorylase.

Question 38

Explain why patients with McArdle disease do not accumulate lactate during light exercise.

Question 39

Insulin binds to its receptor and causes what protein to be activated in the cytoplasm?

Question 40

At the center of a glycogen molecule is:

A) glucose.
B) glycogenin.
C) UDP-glucose.
D) glycogen synthase.
E) glycogen phosphorylase.

Question 41

Give the reaction catalyzed by UDP-glucose pyrophosphorylase.

Question 42

How does insulin stimulate glycogen synthesis?

Question 43

What did Carl and Gerti Cori discover about the cause of von Gierke disease? Briefly explain how this information helps to explain the symptoms of the disease.

Question 44

Explain how the formation of UDP-glucose from glucose 1-phosphate and UTP is essentially reversible.