Question 1

Avidin,a protein intact in raw egg whites,prevents the absorption of biotin in the intestine resulting in biotin deficiency.Which of the following is affected in individuals who consume large amounts of raw egg?

Accepted Answer

A) Oxaloacetate $\to$ phosphoenolpyruvate 
B) 1,3-Bisphosphoglycerate $\to$ glyceraldehyde-3-phosphate 
C) Fructose-1,6-bisphosphate $\to$fructose-6-phosphate 
D) Pyruvate $\to$ oxaloacetate 
E) Phosphoenolpyruvate $\to$ 2-phosphoglycerate

Question 2

Which of the following enzymes catalyzes the conversion of glucose-1-phosphate to glucose-6-phosphate?

Accepted Answer

A) glucose-1-isomerase 
B) glucokinase 
C) glucose-1-phosphatase 
D) phosphoglucomutase 
E) glycogen phosphorylase

Question 3

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Glucose can be synthesized from noncarbohydrate precursors by______.

Accepted Answer

A)  phosphorylase a 
B)  gluconeogenesis 
C)  glucagon 
D)  glucose-6-phosphatase 
E)  cAMP
F)  biotin
G)  insulin
H) glycogenolysis
I) liver
J) glucose-1-phosphate
K) dolichol
L) muscle

Question 4

Matching
Choose the correct answer from the list.Not all the answers will be used.

-An enzyme present in the endoplasmic reticulum of liver cells is ______.

Accepted Answer

A)  phosphorylase a 
B)  gluconeogenesis 
C)  glucagon 
D)  glucose-6-phosphatase 
E)  cAMP
F)  biotin
G)  insulin
H) glycogenolysis
I) liver
J) glucose-1-phosphate
K) dolichol
L) muscle

Question 5

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Low blood glucose (< 5mM)levels result in the release of ______.

Accepted Answer

A)  phosphorylase a 
B)  gluconeogenesis 
C)  glucagon 
D)  glucose-6-phosphatase 
E)  cAMP
F)  biotin
G)  insulin
H) glycogenolysis
I) liver
J) glucose-1-phosphate
K) dolichol
L) muscle

Question 6

A deficiency in the enzyme PEPCK (PEP carboxykinase)would

Accepted Answer

A) block function of the malate/aspartate shuttle. 
B) block transfer of reducing equivalents across the membrane in the heart and liver. 
C) inhibit formation of ATP via oxidative phosphorylation. 
D) inhibit formation of NADH. 
E) decrease flux through gluconeogenesis.

Question 7

What is the net energetic cost of converting two pyruvate to one glucose by gluconeogenesis in ATP equivalents?

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 6 
E) 8

Question 8

A deficiency in muscle glycogen phosphorylase would result in

Accepted Answer

A) normal muscle glycogen structure. 
B) abnormal muscle glycogen structure. 
C) elevated muscle glycogen levels 
D) A and C 
E) B and C

Question 9

Levels of glucose-6-phosphate (G6P)are affected by which of the following?
(I)glycogen breakdown
(II)activity of the pentose phosphate pathway
(III)galactose preparation for entry into glycolysis

Accepted Answer

A) I,II 
B) I,II,III 
C) III 
D) II, 
E) I,III

Question 10

Which of the following best explains the energetically favorable formation of UDP-glucose in the liver and muscle?

Accepted Answer

A) "$\Delta$G°' for the reaction glucose-1-phosphate + UTP $\to$ UDP-glucose + PPi is very negative." 
B) "$\Delta$G°' for the reaction glucose-1-phosphate + UTP $\to$ UDP-glucose + PPi is very positive." 
C) "$\Delta$G°' for the reaction PPi $\to$ 2Pi is very negative." 
D) "$\Delta$G°' for the reaction PPi $\to$ 2Pi is very positive." 
E) "$\Delta$G°' for the overall reaction is very positive."

Question 11

Muscle cells are not able to supply glucose for other tissues because

Accepted Answer

A) they lack the GLUT2 transporter. 
B) they lack pyruvate carboxylase. 
C) they lack glucose-6-phosphatase. 
D) they lack the malate-aspartate shuttle. 
E) they lack glycogen phosphorylase.

Question 12

Which of the following describes a sequence which will ultimately activate glycogen breakdown in a muscle?

Accepted Answer

A) epinephrine binds β receptors.$\to$cAMP $\to$ PKA $\to$phosphorylase kinase $\to$glycogen phosphorylase 
B) epinephrine bind α receptors $\to$ Ca2+ increase $\to$phosphorylase kinase $\to$ glycogen phosphorylase 
C) glucagon $\to$ glucagon receptors $\to$ cAMP $\to$ PKA $\to$ phosphorylase kinase $\to$ glycogen phosphorylase 
D) PP1 binding to unphosphorylated Gm $\to$ dephosphorylates glycogen phosphorylase and phosphorylase kinase 
E) All of these will activate glycogen breakdown in a muscle.

Question 13

The Cori cycle is effective because

Accepted Answer

A) it allows the use of the lactate generated during anaerobic glycolysis to produce pyruvate. 
B) it uses less ATP than gluconeogenesis. 
C) it uses the compound DHAP and G3P generated during glycolysis to transport reducing equivalents. 
D) A and B 
E) A and C

Question 14

In glycogen synthesis,the intermediate between glucose-1-phosphate and glycogen is

Accepted Answer

A) UDP-glucose . 
B) UDP-glycogen. 
C) glucose-1,6-bisphosphate. 
D) glucose-6-phosphate. 
E) glucose.

Question 15

The breakdown of glycogen produces G1P.Which of the following is FALSE regarding G1P?

Accepted Answer

A) It is involved in the utilization of fructose by glycolysis in the liver. 
B) It is involved in the utilization of fructose by glycolysis in the muscle. 
C) It is involved in utilization of galactose by glycolysis. 
D) It is converted to G6P by phosphoglucoisomerase (PGI). 
E) It is produced as an intermediate in the central glycolytic sequence.

Question 16

Which enzyme has an intermediate of the form presented below?

Accepted Answer

A) phosphofructokinase 
B) glycogen phosphorylase 
C) phosphohexose isomerase 
D) phosphoglucomutase 
E) none of the above

Question 17

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Both glycogen synthesis and glycogen breakdown share the metabolite ______.

Accepted Answer

A)  phosphorylase a 
B)  gluconeogenesis 
C)  glucagon 
D)  glucose-6-phosphatase 
E)  cAMP
F)  biotin
G)  insulin
H) glycogenolysis
I) liver
J) glucose-1-phosphate
K) dolichol
L) muscle

Question 18

Hexokinase does not catalyze the final step in gluconeogenesis as written below because
Glucose-6-phosphate + ADP $\to$ glucose + ATP

Accepted Answer

A) the phosphate bond in glucose-6-phosphate does not have a high enough free energy to form ATP. 
B) ATP inhibits hexokinase and blocks the reaction from occurring as written. 
C) hexokinase is only reversible when high levels of ATP are present. 
D) hexokinase does not bind glucose-6-phosphate. 
E) none of the above

Question 19

If cAMP levels are high
(I)Glycogenolysis will occur in muscle cells but not liver cells.
(II)Glucose released from muscle glycogen will enter glycolysis.
(III)Glucose released from liver glycogen will exit liver cells via the GLUT4 transporter.
(IV)Glucose will enter liver cells resulting in glycogen synthesis.

Accepted Answer

A) I,II,IV 
B) I,II 
C) II,III,IV 
D) II only 
E) III only

Question 20

Which of the following will NOT activate glycogen phosphorylase in the liver?

Accepted Answer

A) epinephrine 
B) glucagon 
C) eating a high carbohydrate meal 
D) cAMP 
E) All of the above will activate glycogen phosphorylase.

Exam 16: Glycogen Metabolism and Gluconeogenesis

Avidin,a protein intact in raw egg whites,prevents the absorption of biotin in the intestine resulting in biotin deficiency.Which of the following is affected in individuals who consume large amounts of raw egg?

Which of the following enzymes catalyzes the conversion of glucose-1-phosphate to glucose-6-phosphate?

Matching Choose the correct answer from the list.Not all the answers will be used. -Glucose can be synthesized from noncarbohydrate precursors by______.

Matching Choose the correct answer from the list.Not all the answers will be used. -An enzyme present in the endoplasmic reticulum of liver cells is ______.

Matching Choose the correct answer from the list.Not all the answers will be used. -Low blood glucose (< 5mM) levels result in the release of ______.

A deficiency in the enzyme PEPCK (PEP carboxykinase) would

What is the net energetic cost of converting two pyruvate to one glucose by gluconeogenesis in ATP equivalents?

A deficiency in muscle glycogen phosphorylase would result in

Levels of glucose-6-phosphate (G6P) are affected by which of the following? (I) glycogen breakdown (II) activity of the pentose phosphate pathway (III) galactose preparation for entry into glycolysis

Which of the following best explains the energetically favorable formation of UDP-glucose in the liver and muscle?

Muscle cells are not able to supply glucose for other tissues because

Which of the following describes a sequence which will ultimately activate glycogen breakdown in a muscle?

The Cori cycle is effective because

In glycogen synthesis,the intermediate between glucose-1-phosphate and glycogen is

The breakdown of glycogen produces G1P.Which of the following is FALSE regarding G1P?

Which enzyme has an intermediate of the form presented below?

Matching Choose the correct answer from the list.Not all the answers will be used. -Both glycogen synthesis and glycogen breakdown share the metabolite ______.

Hexokinase does not catalyze the final step in gluconeogenesis as written below because Glucose-6-phosphate + ADP $\to$ glucose + ATP

Which of the following will NOT activate glycogen phosphorylase in the liver?

Exam 16: Glycogen Metabolism and Gluconeogenesis

Avidin,a protein intact in raw egg whites,prevents the absorption of biotin in the intestine resulting in biotin deficiency.Which of the following is affected in individuals who consume large amounts of raw egg?

Which of the following enzymes catalyzes the conversion of glucose-1-phosphate to glucose-6-phosphate?

Matching Choose the correct answer from the list.Not all the answers will be used. -Glucose can be synthesized from noncarbohydrate precursors by______.

Matching Choose the correct answer from the list.Not all the answers will be used. -An enzyme present in the endoplasmic reticulum of liver cells is ______.

Matching Choose the correct answer from the list.Not all the answers will be used. -Low blood glucose (< 5mM) levels result in the release of ______.

A deficiency in the enzyme PEPCK (PEP carboxykinase) would

What is the net energetic cost of converting two pyruvate to one glucose by gluconeogenesis in ATP equivalents?

A deficiency in muscle glycogen phosphorylase would result in

Levels of glucose-6-phosphate (G6P) are affected by which of the following? (I) glycogen breakdown (II) activity of the pentose phosphate pathway (III) galactose preparation for entry into glycolysis

Which of the following best explains the energetically favorable formation of UDP-glucose in the liver and muscle?

Muscle cells are not able to supply glucose for other tissues because

Which of the following describes a sequence which will ultimately activate glycogen breakdown in a muscle?

The Cori cycle is effective because

In glycogen synthesis,the intermediate between glucose-1-phosphate and glycogen is

The breakdown of glycogen produces G1P.Which of the following is FALSE regarding G1P?

Which enzyme has an intermediate of the form presented below?

Matching Choose the correct answer from the list.Not all the answers will be used. -Both glycogen synthesis and glycogen breakdown share the metabolite ______.

Hexokinase does not catalyze the final step in gluconeogenesis as written below because Glucose-6-phosphate + ADP →\to→ glucose + ATP

Which of the following will NOT activate glycogen phosphorylase in the liver?

Hexokinase does not catalyze the final step in gluconeogenesis as written below because Glucose-6-phosphate + ADP $\to$ glucose + ATP