Question 1

In the elongation of glycogen, activated glucose units are attached to which hydroxyl of the terminal residue of the growing glycogen chain?

Accepted Answer

A)  C-1 
B)  C-3 
C)  C-4 
D)  C-6 
A)  C-1 
B)  C-3 
C)  C-4 
D)  C-6

Question 2

The debranching enzyme does NOT catalyze the

Accepted Answer

A)  formation of $\alpha$(1,6) linkages. 
B)  cleavage of $\alpha$(1,6) linkages. 
C)  formation of $\alpha$(1,4) linkages. 
D)  cleavage of $\alpha$(1,4) linkages. 
A)  formation of $\alpha$(1,6) linkages. 
B)  cleavage of $\alpha$(1,6) linkages. 
C)  formation of $\alpha$(1,4) linkages. 
D)  cleavage of $\alpha$(1,4) linkages.

Question 3

Which of the following is NOT a role played by the pentose phosphate pathway?

Accepted Answer

A)  converting pyruvate into TCA cycle intermediates 
B)  making NADPH for other metabolic pathways 
C)  converting 6C glucose into 5C ribose 
D)  converting DNA backbone sugars into glycolysis intermediates 
A)  converting pyruvate into TCA cycle intermediates 
B)  making NADPH for other metabolic pathways 
C)  converting 6C glucose into 5C ribose 
D)  converting DNA backbone sugars into glycolysis intermediates

Question 4

Which pair of opposite enzymes in the glycolysis and gluconeogenesis pathway are not allosterically regulated but rather regulated by compartmentalization?

Accepted Answer

A)  pyruvate kinase/PEP carboxykinase 
B)  phosphofructokinase 1/fructose-1,6-bisphosphatase 
C)  phosphofructokinase 2/fructose-2,6-bisphosphatase 
D)  hexokinase/glucose-6-phosphatase 
A)  pyruvate kinase/PEP carboxykinase 
B)  phosphofructokinase 1/fructose-1,6-bisphosphatase 
C)  phosphofructokinase 2/fructose-2,6-bisphosphatase 
D)  hexokinase/glucose-6-phosphatase

Question 5

In the breakdown of glycogen, the debranching enzyme catalyzes the formation of

Accepted Answer

A)  "glucose-1-phosphate." 
B)  "glucose." 
C)  "$\alpha$(1,6) branched glycogen." 
D)  "glucose-6-phosphate." 
A)  "glucose-1-phosphate." 
B)  "glucose." 
C)  "$\alpha$(1,6) branched glycogen." 
D)  "glucose-6-phosphate."

Question 6

Which of the following molecules is found in the nonoxidative phase of the pentose phosphate pathway?

Accepted Answer

A)  glucose-6-phosphate 
B)  sedoheptulose-7-phosphate 
C)  phosphoenolpyruvate 
D)  CO2 
A)  glucose-6-phosphate 
B)  sedoheptulose-7-phosphate 
C)  phosphoenolpyruvate 
D)  CO2

Question 7

Which of the following molecules would inhibit the regulated steps in gluconeogenesis?

Accepted Answer

A)  ATP 
B)  ADP 
C)  pyruvate 
D)  NADH 
A)  ATP 
B)  ADP 
C)  pyruvate 
D)  NADH

Question 8

Name the enzymes that catalyze the two opposing glycogen polymerization and depolymerization reactions found in glycogen synthesis and glycogen breakdown.

Accepted Answer

Glycogen synthase catalyzes gl

Question 9

Which enzyme uses cellular NADPH to regenerate reduced glutathione?

Accepted Answer

A)  glucose-6-phosphate dehydrogenase 
B)  glutathione peroxidase 
C)  glutathione reductase 
D)  hemoglobin 
A)  glucose-6-phosphate dehydrogenase 
B)  glutathione peroxidase 
C)  glutathione reductase 
D)  hemoglobin

Question 10

What class of biomolecule is glycogenin?

Accepted Answer

A)  hormone 
B)  carbohydrate 
C)  enzyme 
D)  lipid 
A)  hormone 
B)  carbohydrate 
C)  enzyme 
D)  lipid

Question 11

The activation of glycogen phosphorylase will lead to a(n) in blood glucose concentrations and is stimulated by the hormone _.

Accepted Answer

A)  decrease; insulin 
B)  decrease; glucagon 
C)  increase; insulin 
D)  increase; glucagon 
A)  decrease; insulin 
B)  decrease; glucagon 
C)  increase; insulin 
D)  increase; glucagon

Question 12

Which one of the following is involved in the breakdown of glycogen?

Accepted Answer

A)  inorganic phosphate 
B)  ATP 
C)  branching enzyme 
D)  hexokinase 
A)  inorganic phosphate 
B)  ATP 
C)  branching enzyme 
D)  hexokinase

Question 13

In the glycogenesis pathway, what is the leaving group in the last step where glucose is added to the growing glycogen chain?

Accepted Answer

A)  UDP-glucose 
B)  pi 
C)  glucose-1-phosphate 
D)  UDP 
A)  UDP-glucose 
B)  pi 
C)  glucose-1-phosphate 
D)  UDP

Question 14

The regulated reactions of gluconeogenesis have/are

Accepted Answer

A)  large positive $\Delta$G values. 
B)  those that are counter to regulated reactions in glycolysis. 
C)  reversible reactions. 
D)  activated by molecules indicating a low energy charge in the cell. 
A)  large positive $\Delta$G values. 
B)  those that are counter to regulated reactions in glycolysis. 
C)  reversible reactions. 
D)  activated by molecules indicating a low energy charge in the cell.

Question 15

What is the overall net reaction of the pentose phosphate pathway, where glucose-
6-phosphate is entirely converted to CO2? Please include any cofactors produced for the cell.

Accepted Answer

glucose-6-phosphate + 12 NADP<

Question 16

Draw the structure of the short glycogen disaccharide linked to glycogenin through its tyrosine amino acid.

Accepted Answer

The answer of Draw the structure of the short glycogen...

Question 17

The main function of the pentose phosphate pathway is to provide

Accepted Answer

A)  the cell with backup capability when glycolysis is inhibited. 
B)  energy and reducing power. 
C)  a mechanism for the utilization of the carbon skeletons of excess amino acids. 
D)  a source of ribose and NADPH. 
A)  the cell with backup capability when glycolysis is inhibited. 
B)  energy and reducing power. 
C)  a mechanism for the utilization of the carbon skeletons of excess amino acids. 
D)  a source of ribose and NADPH.

Question 18

In the glycogenesis pathway, the role of the glucose-6-phosphate isomerization reaction is to

Accepted Answer

A)  create a more stable intermediate for the subsequent reaction. 
B)  decrease the concentration of glucose-6-phosphate, thereby driving the pathway forward. 
C)  ensure that the charged molecule stays in the cell. 
D)  prepare the anomeric carbon for nucleophilic attack. 
A)  create a more stable intermediate for the subsequent reaction. 
B)  decrease the concentration of glucose-6-phosphate, thereby driving the pathway forward. 
C)  ensure that the charged molecule stays in the cell. 
D)  prepare the anomeric carbon for nucleophilic attack.

Question 19

How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  4 
A)  0 
B)  1 
C)  2 
D)  4

Question 20

What is the cellular role of glutathione in red blood cells?

Accepted Answer

Glutathione acts as an antioxidant to pr

Exam 14: Carbohydrate Metabolism

In the elongation of glycogen, activated glucose units are attached to which hydroxyl of the terminal residue of the growing glycogen chain?

The debranching enzyme does NOT catalyze the

Which of the following is NOT a role played by the pentose phosphate pathway?

Which pair of opposite enzymes in the glycolysis and gluconeogenesis pathway are not allosterically regulated but rather regulated by compartmentalization?

In the breakdown of glycogen, the debranching enzyme catalyzes the formation of

Which of the following molecules is found in the nonoxidative phase of the pentose phosphate pathway?

Which of the following molecules would inhibit the regulated steps in gluconeogenesis?

Name the enzymes that catalyze the two opposing glycogen polymerization and depolymerization reactions found in glycogen synthesis and glycogen breakdown.

Which enzyme uses cellular NADPH to regenerate reduced glutathione?

What class of biomolecule is glycogenin?

The activation of glycogen phosphorylase will lead to a(n) in blood glucose concentrations and is stimulated by the hormone _.

Which one of the following is involved in the breakdown of glycogen?

In the glycogenesis pathway, what is the leaving group in the last step where glucose is added to the growing glycogen chain?

The regulated reactions of gluconeogenesis have/are

What is the overall net reaction of the pentose phosphate pathway, where glucose- 6-phosphate is entirely converted to CO2? Please include any cofactors produced for the cell.

Draw the structure of the short glycogen disaccharide linked to glycogenin through its tyrosine amino acid.

The main function of the pentose phosphate pathway is to provide

In the glycogenesis pathway, the role of the glucose-6-phosphate isomerization reaction is to

How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

What is the cellular role of glutathione in red blood cells?

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

Filters

What is the overall net reaction of the pentose phosphate pathway, where glucose- 6-phosphate is entirely converted to CO₂? Please include any cofactors produced for the cell.