Question 1

Phosphoprotein phosphatase -1 (PP1)

Accepted Answer

A) catalyzes the phosphorylation of phosphorylase kinase. 
B) increases glycogen breakdown when active. 
C) catalyzes the dephosphorylation of phosphorylase kinase. 
D) catalyzes the dephosphorylation of glycogen phosphorylase. 
E) Both C and Dare correct. 
A) catalyzes the phosphorylation of phosphorylase kinase. 
B) increases glycogen breakdown when active. 
C) catalyzes the dephosphorylation of phosphorylase kinase. 
D) catalyzes the dephosphorylation of glycogen phosphorylase. 
E) Both C and Dare correct.

Question 2

Which enzyme below is NOT required for the synthesis of branched glycogen?

Accepted Answer

A) glycogen phosphorylase 
B) glycogen synthase 
C) branching enzyme 
D) phosphoglucomutase 
E) All are required for synthesis of glycogen. 
A) glycogen phosphorylase 
B) glycogen synthase 
C) branching enzyme 
D) phosphoglucomutase 
E) All are required for synthesis of glycogen.

Question 3

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

Accepted Answer

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

Question 4

Which of the following metabolic conversions does not occur in gluconeogenesis?

Accepted Answer

A) oxaloacetate $\rarr$phosphoenolpyruvate 
B) fructose-1,6-bisphosphate $\rarr$fructose-6-phosphate 
C) GTP $\rarr$ CO2 + GDP 
D) NADH + H+ $\rarr$ NAD+ 
E) 1,3-bisphosphoglycerate $\rarr$ 3-phosphoglycerate 
A) oxaloacetate $\rarr$phosphoenolpyruvate 
B) fructose-1,6-bisphosphate $\rarr$fructose-6-phosphate 
C) GTP $\rarr$ CO2 + GDP 
D) NADH + H+ $\rarr$ NAD+ 
E) 1,3-bisphosphoglycerate $\rarr$ 3-phosphoglycerate

Question 5

Which of the following serves as the free energy source for the metabolic conversion of oxaloacetate to phosphoenolpyruvate, which is catalyzed by PEP carboxykinase?

Accepted Answer

A) hydrolysis of PPi 
B) hydrolysis of ATP 
C) hydrolysis of GTP 
D) hydrolysis of an internal phosphoanhydride bond 
E) hydrolysis of a thioester intermediate 
A) hydrolysis of PPi 
B) hydrolysis of ATP 
C) hydrolysis of GTP 
D) hydrolysis of an internal phosphoanhydride bond 
E) hydrolysis of a thioester intermediate

Question 6

Hexokinase does not catalyze the final step in gluconeogenesis as written below because glucose-6-phosphate + ADP $\rarr$  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 
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 7

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 
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 8

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 α 
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 
A) phosphorylase α 
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 9

Which of the following aides in formation of a primer for glycogen synthesis ?

Accepted Answer

A) glycogen synthase 
B) UDP-glucose pyrophosphatate 
C) glycogenin 
D) UDP-glycogen 
E) amylo-(1,4$\rarr$1,6)-transglycosylase 
A) glycogen synthase 
B) UDP-glucose pyrophosphatate 
C) glycogenin 
D) UDP-glycogen 
E) amylo-(1,4$\rarr$1,6)-transglycosylase

Question 10

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Carboxylation of pyruvate in humans requires ______ as an essential dietary nutrient.

Accepted Answer

A) phosphorylase α 
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 
A) phosphorylase α 
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 11

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 α 
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 
A) phosphorylase α 
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 12

The biotin prosthetic group of pyruvate carboxylase is covalently attached to a ______ residue of the enzyme?

Accepted Answer

A) valine 
B) serine 
C) lysine 
D) arginine 
E) the biotin is attached non-covalently 
A) valine 
B) serine 
C) lysine 
D) arginine 
E) the biotin is attached non-covalently

Question 13

Which of the following best describes the function of the glycogen debranching enzyme in glycogenolysis?

Accepted Answer

A) It cleaves $\alpha$(1$\rarr$6)branch points releasing glucose-6-phosphate. 
B) It cleaves $\alpha$(1$\rarr$6)branch points releasing glucose-1-phosphate. 
C) It cleaves $\alpha$(1$\rarr$6)branch points releasing glucose. 
D) It transfers an $\alpha$(1$\rarr$4)linked trisaccharide unit to the nonreducing end of an alternate branch, then cleaves the $\alpha$(1$\rarr$6)branch point releasing glucose-1-phosphate. 
E) It transfers an $\alpha$(1$\rarr$4)linked trisaccharide to the nonreducing end of an alternate branch, then cleaves the $\alpha$(1$\rarr$6)branch point releasing glucose. 
A) It cleaves $\alpha$(1$\rarr$6)branch points releasing glucose-6-phosphate. 
B) It cleaves $\alpha$(1$\rarr$6)branch points releasing glucose-1-phosphate. 
C) It cleaves $\alpha$(1$\rarr$6)branch points releasing glucose. 
D) It transfers an $\alpha$(1$\rarr$4)linked trisaccharide unit to the nonreducing end of an alternate branch, then cleaves the $\alpha$(1$\rarr$6)branch point releasing glucose-1-phosphate. 
E) It transfers an $\alpha$(1$\rarr$4)linked trisaccharide to the nonreducing end of an alternate branch, then cleaves the $\alpha$(1$\rarr$6)branch point releasing glucose.

Question 14

The synthesis of N-linked oligosaccharides occur in the _____ while O-linked oligosaccharides are synthesized in the ______.

Accepted Answer

A) Golgi apparatus; endoplasmic reticulum 
B) cytosol; Golgi apparatus 
C) mitochondrial matrix; endoplasmic reticulum 
D) endoplasmic reticulum; Golgi apparatus 
E) Golgi apparatus; mitochondrial matrix 
A) Golgi apparatus; endoplasmic reticulum 
B) cytosol; Golgi apparatus 
C) mitochondrial matrix; endoplasmic reticulum 
D) endoplasmic reticulum; Golgi apparatus 
E) Golgi apparatus; mitochondrial matrix

Question 15

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-______ cells lack receptors for the hormone glucagon.

Accepted Answer

A) phosphorylase α 
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 
A) phosphorylase α 
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 16

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. 
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 17

Which of the following is correct concerning the metabolic reaction shown below? Pyruvate + CO2 + ATP SYMBOL 174 \f "Symbol" oxaloacetate + ADP + Pi
I.This metabolic reaction is catalyzed by pyruvate carboxykinase.
II.The enzyme that catalyzes this reaction is activated by high concentrations of acetyl-CoA .
III.The enzyme that catalyzes this reaction is covalently bonded to the coenzyme pyridoxal-5ꞌ-phosphate.
IV.The enzyme that catalyzes this reaction is located in the endoplasmic reticulum of the cell .

Accepted Answer

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

Question 18

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-The first step in the breakdown of glycogen is catalyzed by ______.

Accepted Answer

A) phosphorylase α 
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 
A) phosphorylase α 
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 19

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. 
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 20

Which of the following best describes the role of fructose-2,6-bisphosphate (FBP)in liver cells?

Accepted Answer

A) It is an intermediate in glycolysis. 
B) It is an intermediate in gluconeogenesis. 
C) It is an intermediate in both glycolysis and gluconeogenesis. 
D) FBP is a potent allosteric activator of phosphofructokinase and an inhibitor of fructose bisphosphatase. 
E) FBP is a potent allosteric activator of fructose bisphosphatase and an inhibitor of phosphofructokinase. 
A) It is an intermediate in glycolysis. 
B) It is an intermediate in gluconeogenesis. 
C) It is an intermediate in both glycolysis and gluconeogenesis. 
D) FBP is a potent allosteric activator of phosphofructokinase and an inhibitor of fructose bisphosphatase. 
E) FBP is a potent allosteric activator of fructose bisphosphatase and an inhibitor of phosphofructokinase.

Exam 15: Glycogen Metabolism and Gluconeogenesis

Phosphoprotein phosphatase -1 (PP1)

Which enzyme below is NOT required for the synthesis of branched glycogen?

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

Which of the following metabolic conversions does not occur in gluconeogenesis?

Which of the following serves as the free energy source for the metabolic conversion of oxaloacetate to phosphoenolpyruvate, which is catalyzed by PEP carboxykinase?

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

The Cori cycle is effective because

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 ______.

Which of the following aides in formation of a primer for glycogen synthesis ?

Matching Choose the correct answer from the list. Not all the answers will be used. -Carboxylation of pyruvate in humans requires ______ as an essential dietary nutrient.

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

The biotin prosthetic group of pyruvate carboxylase is covalently attached to a ______ residue of the enzyme?

Which of the following best describes the function of the glycogen debranching enzyme in glycogenolysis?

The synthesis of N-linked oligosaccharides occur in the _____ while O-linked oligosaccharides are synthesized in the ______.

Matching Choose the correct answer from the list. Not all the answers will be used. -______ cells lack receptors for the hormone glucagon.

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

Matching Choose the correct answer from the list. Not all the answers will be used. -The first step in the breakdown of glycogen is catalyzed by ______.

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

Which of the following best describes the role of fructose-2,6-bisphosphate (FBP)in liver cells?

Introduction to the Chemistry of Life

Water

Nucleotides, Nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, Inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

Dna Replication, Repair and Recombination

Transcription and Rna Processing

Translation

Regulation of Gene Expression

Filters

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

The synthesis of N-linked oligosaccharides occur in the _ while O-linked oligosaccharides are synthesized in the __.