Question 1

Which of the following class of enzymes does glyceraldehyde-3-phosphate dehydrogenase belong to?

Accepted Answer

A) oxidoreductases 
B) isomerases 
C) transferases 
D) hydrolases 
A) oxidoreductases 
B) isomerases 
C) transferases 
D) hydrolases A

Question 2

Which of the following enzymes catalyzes a reversible reaction that is an equilibrium-controlled step of glycolysis?

Accepted Answer

A) pyruvate kinase 
B) aldolase 
C) phosphofructokinase-1 
D) glucokinase 
A) pyruvate kinase 
B) aldolase 
C) phosphofructokinase-1 
D) glucokinase A

Question 3

Which of the following is a characteristic of fructose bisphosphate aldolase in animal tissues?

Accepted Answer

A) It is a Class II aldolase. 
B) It belongs to the transferase class of enzymes. 
C) The reaction is reversible in erythrocytes (∆G is very small). 
D) The products are an aldopentose phosphate and a ketotriose phosphate. 
A) It is a Class II aldolase. 
B) It belongs to the transferase class of enzymes. 
C) The reaction is reversible in erythrocytes (∆G is very small). 
D) The products are an aldopentose phosphate and a ketotriose phosphate. C

Question 4

What is the net yield of the oxidation of 1 mole of glucose by anaerobic glycolysis?

Accepted Answer

A) 2 moles of pyruvate and 2 moles of ATP 
B) 2 moles of lactate,2 moles of NADH,and 2 moles of ATP 
C) 2 moles of pyruvate,2 moles of NADH,and 4 moles of ATP 
D) 2 moles of lactate and 2 moles of ATP 
A) 2 moles of pyruvate and 2 moles of ATP 
B) 2 moles of lactate,2 moles of NADH,and 2 moles of ATP 
C) 2 moles of pyruvate,2 moles of NADH,and 4 moles of ATP 
D) 2 moles of lactate and 2 moles of ATP

Question 5

Which of the following is a step in the phosphoglucoisomerase-catalyzed reaction on glucose-6-phosphate?

Accepted Answer

A) C-4 proton is removed 
B) creation of a carbonyl group at C-1 
C) opening of the pyranose ring 
D) removal of a furanose ring 
A) C-4 proton is removed 
B) creation of a carbonyl group at C-1 
C) opening of the pyranose ring 
D) removal of a furanose ring

Question 6

Addition of water across a double bond,or removal of water to form a double bond,is catalyzed by a subclass of the lyase class of enzymes.Which of the following enzymes would be a lyase?

Accepted Answer

A) glyceraldehyde-3-phosphate dehydrogenase 
B) triose phosphate isomerase (TPI) 
C) phosphoglycerate mutase 
D) enolase 
A) glyceraldehyde-3-phosphate dehydrogenase 
B) triose phosphate isomerase (TPI) 
C) phosphoglycerate mutase 
D) enolase

Question 7

Which of the of the following covalent modifications does cAMP-dependent protein kinase carry out on pyruvate kinase?

Accepted Answer

A) carboxylation 
B) phosphorolysis 
C) phosphorylation 
D) decarboxylation 
A) carboxylation 
B) phosphorolysis 
C) phosphorylation 
D) decarboxylation

Question 8

Which of the following are the 3 main products of glycolysis?

Accepted Answer

A) ATP;pyruvate;NAD⁺ 
B) NAD⁺;ADP;FAD 
C) ATP;NAD⁺;ADP 
D) ATP;pyruvate;NADH 
A) ATP;pyruvate;NAD⁺ 
B) NAD⁺;ADP;FAD 
C) ATP;NAD⁺;ADP 
D) ATP;pyruvate;NADH

Question 9

What happens to lactate after it is produced by anaerobic muscle tissue?

Accepted Answer

A) It is stored in muscle until oxygen is available. 
B) It is carried by the blood to the liver for gluconeogenesis back to glycogen. 
C) It is further oxidized to acetate in muscle. 
D) It is transferred to erythrocytes to release oxygen from hemoglobin. 
A) It is stored in muscle until oxygen is available. 
B) It is carried by the blood to the liver for gluconeogenesis back to glycogen. 
C) It is further oxidized to acetate in muscle. 
D) It is transferred to erythrocytes to release oxygen from hemoglobin.

Question 10

PEP and 2-PG have similar amounts of potential metabolic energy with respect to decomposition to Pᵢ,CO₂,and H₂O.Which of the following statements applies to enolase-catalyzed decomposition of PEP and 2-PG?

Accepted Answer

A) The enolase reaction creates a much more unstable reactive intermediate. 
B) The enolase reaction rearranges 2-PG into a form from which more potential energy can be released by hydrolysis. 
C) The enolase reaction rearranges 2-PG to a form with greater binding potential to the enzyme. 
D) The enolase reaction changes the ∆G of the reaction to increase the potential energy. 
A) The enolase reaction creates a much more unstable reactive intermediate. 
B) The enolase reaction rearranges 2-PG into a form from which more potential energy can be released by hydrolysis. 
C) The enolase reaction rearranges 2-PG to a form with greater binding potential to the enzyme. 
D) The enolase reaction changes the ∆G of the reaction to increase the potential energy.

Question 11

Where does glycerol generated by hydrolysis of triacylglycerols enter glycolysis?

Accepted Answer

A) at the glyceraldehyde-3-phosphate stage 
B) at the 3-phosphoglycerate stage 
C) at the 2-phosphoglycerate stage 
D) at the dihydroxyacetone phosphate stage 
A) at the glyceraldehyde-3-phosphate stage 
B) at the 3-phosphoglycerate stage 
C) at the 2-phosphoglycerate stage 
D) at the dihydroxyacetone phosphate stage

Question 12

Which of the following processes do mutases catalyze?

Accepted Answer

A) movement of a functional group within a substrate molecule 
B) phosphorylation from ATP 
C) hydrolysis of a phosphate ester 
D) addition of water across a double bond 
A) movement of a functional group within a substrate molecule 
B) phosphorylation from ATP 
C) hydrolysis of a phosphate ester 
D) addition of water across a double bond

Question 13

Which of the following enzymes of glycolysis is NOT allosterically regulated?

Accepted Answer

A) phosphofructokinase-1 
B) glyceraldehyde-3-phosphate dehydrogenase 
C) hexokinase 
D) pyruvate kinase 
A) phosphofructokinase-1 
B) glyceraldehyde-3-phosphate dehydrogenase 
C) hexokinase 
D) pyruvate kinase

Question 14

Which of the following enzymes converts UDP-galactose to UDP-glucose?

Accepted Answer

A) galactokinase 
B) galactose-uridylyl transferase 
C) UDP-glucose-4-epimerase 
D) UDP-galactose-2-epimerase 
A) galactokinase 
B) galactose-uridylyl transferase 
C) UDP-glucose-4-epimerase 
D) UDP-galactose-2-epimerase

Question 15

Which of the following is a characteristic of type I diabetes mellitus?

Accepted Answer

A) glucokinase induction 
B) low levels of glucokinase 
C) excess insulin production 
D) over production of liver glycogen 
A) glucokinase induction 
B) low levels of glucokinase 
C) excess insulin production 
D) over production of liver glycogen

Question 16

Which of the following enzymes has a mechanism very similar in function to triose phosphate isomerase?

Accepted Answer

A) hexokinase 
B) phosphoglucoisomerase 
C) phosphofructokinase 
D) fructose-1,6-bisphosphate aldolase 
A) hexokinase 
B) phosphoglucoisomerase 
C) phosphofructokinase 
D) fructose-1,6-bisphosphate aldolase

Question 17

Which of the following enzymes catalyzes the step that commits glucose to glycolysis?

Accepted Answer

A) phosphofructokinase-1 (PFK-1) 
B) hexokinase 
C) phosphoglucoisomerase 
D) glucokinase 
A) phosphofructokinase-1 (PFK-1) 
B) hexokinase 
C) phosphoglucoisomerase 
D) glucokinase

Question 18

Which of the following enzymes is defective in the rare hereditary galactosemia?

Accepted Answer

A) galactokinase 
B) galactose-1-phosphate uridylyl transferase 
C) phosphoglucomutase 
D) UDP-glucose pyrophosphorylase 
A) galactokinase 
B) galactose-1-phosphate uridylyl transferase 
C) phosphoglucomutase 
D) UDP-glucose pyrophosphorylase

Question 19

Which of the following substrate carbons is attacked by a cysteine -SH group during the reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase,resulting in the formation of a hemithioacetal?

Accepted Answer

A) alpha 
B) acidic 
C) amino 
D) carbonyl 
A) alpha 
B) acidic 
C) amino 
D) carbonyl

Question 20

Which of the following actions of phosphoglucoisomerase occurs when is secreted by T-cells?

Accepted Answer

A) It phosphorylates galactose. 
B) It isomerizes galactose-6-phosphate to glucose-6-phosphate. 
C) It promotes the survival of certain spinal neurons and sensory nerves. 
D) It glycosylates sphingolipids surrounding nerves. 
A) It phosphorylates galactose. 
B) It isomerizes galactose-6-phosphate to glucose-6-phosphate. 
C) It promotes the survival of certain spinal neurons and sensory nerves. 
D) It glycosylates sphingolipids surrounding nerves.

Exam 17: Glycolysis

Which of the following class of enzymes does glyceraldehyde-3-phosphate dehydrogenase belong to?

Which of the following enzymes catalyzes a reversible reaction that is an equilibrium-controlled step of glycolysis?

Which of the following is a characteristic of fructose bisphosphate aldolase in animal tissues?

What is the net yield of the oxidation of 1 mole of glucose by anaerobic glycolysis?

Which of the following is a step in the phosphoglucoisomerase-catalyzed reaction on glucose-6-phosphate?

Addition of water across a double bond,or removal of water to form a double bond,is catalyzed by a subclass of the lyase class of enzymes.Which of the following enzymes would be a lyase?

Which of the of the following covalent modifications does cAMP-dependent protein kinase carry out on pyruvate kinase?

Which of the following are the 3 main products of glycolysis?

What happens to lactate after it is produced by anaerobic muscle tissue?

PEP and 2-PG have similar amounts of potential metabolic energy with respect to decomposition to Pᵢ,CO₂,and H₂O.Which of the following statements applies to enolase-catalyzed decomposition of PEP and 2-PG?

Where does glycerol generated by hydrolysis of triacylglycerols enter glycolysis?

Which of the following processes do mutases catalyze?

Which of the following enzymes of glycolysis is NOT allosterically regulated?

Which of the following enzymes converts UDP-galactose to UDP-glucose?

Which of the following is a characteristic of type I diabetes mellitus?

Which of the following enzymes has a mechanism very similar in function to triose phosphate isomerase?

Which of the following enzymes catalyzes the step that commits glucose to glycolysis?

Which of the following enzymes is defective in the rare hereditary galactosemia?

Which of the following substrate carbons is attacked by a cysteine -SH group during the reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase,resulting in the formation of a hemithioacetal?

Which of the following actions of phosphoglucoisomerase occurs when is secreted by T-cells?

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Lipid Biosynthesis

Membranes and Membrane Transport

The Reception and Transmission of Extracellular Information

Enzymes Kinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Nutrition and the Organization of Metabolism

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Nitrogen Acquisition and Amino Acid Metabolism

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Synthesis and Degradation of Nucleotides

Recombinant Dna: Cloning and Creation of Chimeric Genes

DNA Metabolism: Replication, recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Post-Transcriptional Regulation of Gene Expression

Completing the Protein Life Cycle: Folding, processing, and Degradation

Metabolic Integration and Organ Specialization

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