Question 1

The reaction, 1,3-bisphosphoglycerate → 2,3-bisphosphoglycerate, is catalyzed by:

Accepted Answer

A)  bisphosphoglycerate phosphatase. 
B)  bisphosphoglycerate mutase. 
C)  2,3-bisphosphoglycerate synthetases. 
D)  3-phosphoglycerate isomerase. 
E)  1,3-bisphosphoglycerate hydrolase. 
A)  bisphosphoglycerate phosphatase. 
B)  bisphosphoglycerate mutase. 
C)  2,3-bisphosphoglycerate synthetases. 
D)  3-phosphoglycerate isomerase. 
E)  1,3-bisphosphoglycerate hydrolase. B

Question 2

All are allosteric regulators of phosphofructokinase-1 EXCEPT:

Accepted Answer

A)  glucose-6-phosphate by inhibition. 
B)  ATP by inhibition. 
C)  AMP by stimulation. 
D)  citrate by inhibition. 
E)  β-D-fructose-2,6-bisphosphate by stimulation. 
A)  glucose-6-phosphate by inhibition. 
B)  ATP by inhibition. 
C)  AMP by stimulation. 
D)  citrate by inhibition. 
E)  β-D-fructose-2,6-bisphosphate by stimulation. A

Question 3

Glycerol from hydrolysis of triacylglycerols enters glycolysis at:

Accepted Answer

A)  glyceraldehyde-3-phosphate. 
B)  3-phosphoglycerate. 
C)  2-phosphoglycerate. 
D)  dihydroxyacetone phosphate. 
E)  1,3-bisphosphoglycerate. 
A)  glyceraldehyde-3-phosphate. 
B)  3-phosphoglycerate. 
C)  2-phosphoglycerate. 
D)  dihydroxyacetone phosphate. 
E)  1,3-bisphosphoglycerate. D

Question 4

Which of the following enzymes is correctly paired with an activator?

Accepted Answer

A)  hexokinase: ATP 
B)  phosphofructokinase-1: fructose-2,6-bisphosphate 
C)  pyruvate kinase: ADP 
D)  glyceraldehyde-3-phosphate dehydrogenase: NAD+ 
E)  glucokinase: glucose 
A)  hexokinase: ATP 
B)  phosphofructokinase-1: fructose-2,6-bisphosphate 
C)  pyruvate kinase: ADP 
D)  glyceraldehyde-3-phosphate dehydrogenase: NAD+ 
E)  glucokinase: glucose

Question 5

The mechanism of triose phosphate isomerase is very similar in function to:

Accepted Answer

A)  hexokinase. 
B)  phosphoglucoisomerase. 
C)  phosphofructokinase. 
D)  fructose-1,6-bisphosphate aldolase. 
E)  none of the above. 
A)  hexokinase. 
B)  phosphoglucoisomerase. 
C)  phosphofructokinase. 
D)  fructose-1,6-bisphosphate aldolase. 
E)  none of the above.

Question 6

All are true for the isomerase reaction of glucose-6-phosphate to fructose-6-phosphate EXCEPT:

Accepted Answer

A)  Mg2+ is required for activity. 
B)  it is an aldose to ketose isomerization. 
C)  "moving" the carbonyl from C-1 to C-2 creates a new primary alcohol group at C-1. 
D)  the reaction is irreversible with a large negative ΔG. 
E)  the enzyme belongs to the isomerase class of enzymes. 
A)  Mg2+ is required for activity. 
B)  it is an aldose to ketose isomerization. 
C)  "moving" the carbonyl from C-1 to C-2 creates a new primary alcohol group at C-1. 
D)  the reaction is irreversible with a large negative ΔG. 
E)  the enzyme belongs to the isomerase class of enzymes.

Question 7

The most common form of hemolytic anemia can be the result of a genetic defect in:

Accepted Answer

A)  hexokinase. 
B)  PFK-1. 
C)  pyruvate kinase 
D)  phosphoglycerate mutase. 
E)  TPI. 
A)  hexokinase. 
B)  PFK-1. 
C)  pyruvate kinase 
D)  phosphoglycerate mutase. 
E)  TPI.

Question 8

Galactosemic individuals can be treated by ____ and the abnormality may disappear in adults due to metabolism of galactose-1-phosphate by:

Accepted Answer

A)  medication; UDP-glucose pyrophosphorylase. 
B)  medication; UDP-glucose-4-epimerase. 
C)  restrictive diet; phosphoglucomutase. 
D)  restrictive diet; UDP-glucose pyrophosphorylase. 
E)  all of the above. 
A)  medication; UDP-glucose pyrophosphorylase. 
B)  medication; UDP-glucose-4-epimerase. 
C)  restrictive diet; phosphoglucomutase. 
D)  restrictive diet; UDP-glucose pyrophosphorylase. 
E)  all of the above.

Question 9

All are allosteric effectors of pyruvate kinase EXCEPT:

Accepted Answer

A)  pyruvate. 
B)  AMP. 
C)  ATP. 
D)  acetyl-CoA. 
E)  fructose-1,6-bisphosphate. 
A)  pyruvate. 
B)  AMP. 
C)  ATP. 
D)  acetyl-CoA. 
E)  fructose-1,6-bisphosphate.

Question 10

All of the following enzymes of glycolysis are allosterically regulated EXCEPT:

Accepted Answer

A)  phosphofructokinase-1. 
B)  glyceraldehyde-3-phosphate dehydrogenase. 
C)  hexokinase. 
D)  pyruvate kinase. 
E)  none of the above. 
A)  phosphofructokinase-1. 
B)  glyceraldehyde-3-phosphate dehydrogenase. 
C)  hexokinase. 
D)  pyruvate kinase. 
E)  none of the above.

Question 11

In the liver, ____ is used to phosphorylate fructose to ____.

Accepted Answer

A)  phosphofructokinase-1; fructose-6-phosphate 
B)  phosphofructokinase-1; fructose-1-phosphate 
C)  fructokinase; fructose-6-phosphate 
D)  fructokinase; fructose-1-phosphate 
E)  hexokinase; fructose-1-phosphate 
A)  phosphofructokinase-1; fructose-6-phosphate 
B)  phosphofructokinase-1; fructose-1-phosphate 
C)  fructokinase; fructose-6-phosphate 
D)  fructokinase; fructose-1-phosphate 
E)  hexokinase; fructose-1-phosphate

Question 12

The step that commits glucose to glycolysis is catalyzed by:

Accepted Answer

A)  hexokinase. 
B)  pyruvate kinase 
C)  phosphofructokinase-1 (PFK-1). 
D)  glucokinase. 
E)  phosphofructokinase-2 (PFK-2) 
A)  hexokinase. 
B)  pyruvate kinase 
C)  phosphofructokinase-1 (PFK-1). 
D)  glucokinase. 
E)  phosphofructokinase-2 (PFK-2)

Question 13

All are important reasons to phosphorylate glucose in the first step of glycolysis EXCEPT:

Accepted Answer

A)  the large positive free energy is important in getting the pathway started. 
B)  glucose-6-phosphate has a negative charge preventing transport out of the cell. 
C)  the concentration of free glucose in the cell is lowered favoring influx of glucose. 
D)  phosphorylation keeps the glucose in the cell. 
E)  regulatory control can be imposed only at a reaction not at equilibrium. 
A)  the large positive free energy is important in getting the pathway started. 
B)  glucose-6-phosphate has a negative charge preventing transport out of the cell. 
C)  the concentration of free glucose in the cell is lowered favoring influx of glucose. 
D)  phosphorylation keeps the glucose in the cell. 
E)  regulatory control can be imposed only at a reaction not at equilibrium.

Question 14

Which of the following enzymes has two different binding sites for ATP, one a regulatory site and the other a substrate site?

Accepted Answer

A)  hexokinase 
B)  glucokinase 
C)  phosphofructokinase-1 
D)  phosphoglycerate kinase 
E)  pyruvate kinase 
A)  hexokinase 
B)  glucokinase 
C)  phosphofructokinase-1 
D)  phosphoglycerate kinase 
E)  pyruvate kinase

Question 15

If yeast cells were given glucose that was labeled with 14C at carbon 3, where would the 14C by found after glycolysis under anaerobic conditions?

Accepted Answer

A)  CO2 
B)  Ethanol, C1 
C)  Ethanol, C2 
D)  Lactic acid, C1 
E)  Lactic acid, C3 
A)  CO2 
B)  Ethanol, C1 
C)  Ethanol, C2 
D)  Lactic acid, C1 
E)  Lactic acid, C3

Question 16

Lactose synthase is a dimeric complex of:

Accepted Answer

A)  lactose and β-galactosidase. 
B)  galactosyl transferase and lactase. 
C)  α-lactalbumin and galactosyl transferase. 
D)  galactosyl transferase and β-galactosidase. 
E)  α-lactalbumin and β-galactosidase. 
A)  lactose and β-galactosidase. 
B)  galactosyl transferase and lactase. 
C)  α-lactalbumin and galactosyl transferase. 
D)  galactosyl transferase and β-galactosidase. 
E)  α-lactalbumin and β-galactosidase.

Question 17

Class I aldolases are characterized by:

Accepted Answer

A)  an endiol intermediate. 
B)  a requirement for biotin. 
C)  a Schiff base intermediate. 
D)  inhibition by EDTA due to a metal ion requirement. 
E)  coenzyme requirement for thiamin pyrophosphate (TPP). 
A)  an endiol intermediate. 
B)  a requirement for biotin. 
C)  a Schiff base intermediate. 
D)  inhibition by EDTA due to a metal ion requirement. 
E)  coenzyme requirement for thiamin pyrophosphate (TPP).

Question 18

Which of the following enzymes is correctly paired with an inhibitor?

Accepted Answer

A)  hexokinase: ATP 
B)  phosphofructokinase-1: AMP 
C)  pyruvate kinase: ATP 
D)  phosphofructokinase-2: citrate 
E)  glyceraldehyde-3-phosphate dehydrogenase: 1,3-bisphosphoglycerate 
A)  hexokinase: ATP 
B)  phosphofructokinase-1: AMP 
C)  pyruvate kinase: ATP 
D)  phosphofructokinase-2: citrate 
E)  glyceraldehyde-3-phosphate dehydrogenase: 1,3-bisphosphoglycerate

Question 19

All of the following are characteristic of the coupling between glycolysis and the citric acid cycle EXCEPT:

Accepted Answer

A)  glycolysis feeds acetyl CoA, via pyruvate, to the citric acid cycle. 
B)  citrate inhibits glucokinase to regulate glycolysis. 
C)  citrate builds up when citric acid cycle reaches saturation. 
D)  citric acid cycle directs electrons into electron transport chain for the purpose of ATP production. 
E)  ATP production via citric acid cycle, electron transport, and oxidative phosphorylation inhibits glycolysis. 
A)  glycolysis feeds acetyl CoA, via pyruvate, to the citric acid cycle. 
B)  citrate inhibits glucokinase to regulate glycolysis. 
C)  citrate builds up when citric acid cycle reaches saturation. 
D)  citric acid cycle directs electrons into electron transport chain for the purpose of ATP production. 
E)  ATP production via citric acid cycle, electron transport, and oxidative phosphorylation inhibits glycolysis.

Question 20

Which of the following has the most highly exergonic hydrolysis (considering that only the highest energy bond is hydrolyzed)?

Accepted Answer

A)  phosphoenolpyruvate 
B)  fructose-6-phosphate 
C)  1,3-bisphoshpoglycerate 
D)  2,3-bisphoshpoglycerate 
E)  fructose-1,6-bisphosphate 
A)  phosphoenolpyruvate 
B)  fructose-6-phosphate 
C)  1,3-bisphoshpoglycerate 
D)  2,3-bisphoshpoglycerate 
E)  fructose-1,6-bisphosphate

Exam 18: Glycolysis

The reaction, 1,3-bisphosphoglycerate → 2,3-bisphosphoglycerate, is catalyzed by:

All are allosteric regulators of phosphofructokinase-1 EXCEPT:

Glycerol from hydrolysis of triacylglycerols enters glycolysis at:

Which of the following enzymes is correctly paired with an activator?

The mechanism of triose phosphate isomerase is very similar in function to:

All are true for the isomerase reaction of glucose-6-phosphate to fructose-6-phosphate EXCEPT:

The most common form of hemolytic anemia can be the result of a genetic defect in:

Galactosemic individuals can be treated by ____ and the abnormality may disappear in adults due to metabolism of galactose-1-phosphate by:

All are allosteric effectors of pyruvate kinase EXCEPT:

All of the following enzymes of glycolysis are allosterically regulated EXCEPT:

In the liver, ____ is used to phosphorylate fructose to ____.

The step that commits glucose to glycolysis is catalyzed by:

All are important reasons to phosphorylate glucose in the first step of glycolysis EXCEPT:

Which of the following enzymes has two different binding sites for ATP, one a regulatory site and the other a substrate site?

If yeast cells were given glucose that was labeled with 14C at carbon 3, where would the 14C by found after glycolysis under anaerobic conditions?

Lactose synthase is a dimeric complex of:

Class I aldolases are characterized by:

Which of the following enzymes is correctly paired with an inhibitor?

All of the following are characteristic of the coupling between glycolysis and the citric acid cycle EXCEPT:

Which of the following has the most highly exergonic hydrolysis (considering that only the highest energy bond is hydrolyzed)?

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

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

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

The Reception and Transmission of Extracellular Information

Filters

In the liver, is used to phosphorylate fructose to .

If yeast cells were given glucose that was labeled with ¹⁴C at carbon 3, where would the ¹⁴C by found after glycolysis under anaerobic conditions?