Question 1

In the second half of the glycolytic pathway, ____ ATP molecules are produced and with the offset of ____ ATPs consumed in the first half, the net yield is ____ ATPs per glucose.

Accepted Answer

A)  four; four; zero 
B)  four; two; two 
C)  two; two; four 
D)  two; one; one 
E)  four; one; three 
A)  four; four; zero 
B)  four; two; two 
C)  two; two; four 
D)  two; one; one 
E)  four; one; three

Question 2

α-D-Glucose + ATP → ____ + ____ + H+

Accepted Answer

A)  α-D-fructose; ADP 
B)  α-D-glucose-1-phosphate; AMP 
C)  α-D-glucose-1-phosphate; ADP 
D)  α-D-glucose-6-phosphate; ADP 
E)  D-glucose-1,6-bisphosphate; AMP 
A)  α-D-fructose; ADP 
B)  α-D-glucose-1-phosphate; AMP 
C)  α-D-glucose-1-phosphate; ADP 
D)  α-D-glucose-6-phosphate; ADP 
E)  D-glucose-1,6-bisphosphate; AMP

Question 3

The rare hereditary galactosemia involves defects in:

Accepted Answer

A)  galactokinase. 
B)  galactose-1-phosphate uridylyltransferase. 
C)  phosphoglucomutase. 
D)  UDP-glucose-4-epimerase. 
E)  UDP-glucose pyrophosphorylase. 
A)  galactokinase. 
B)  galactose-1-phosphate uridylyltransferase. 
C)  phosphoglucomutase. 
D)  UDP-glucose-4-epimerase. 
E)  UDP-glucose pyrophosphorylase.

Question 4

Glyceraldehyde-3-phosphate dehydrogenase belongs to what class of enzymes?

Accepted Answer

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

Question 5

Substrate-level phosphorylation occurs in glycolysis in the reaction catalyzed by ____ and belongs to ____ class of enzymes.

Accepted Answer

A)  phosphoglycerate kinase; transferase 
B)  hexokinase; transferase 
C)  phosphofructokinase; transferase 
D)  glucokinase; transferase 
E)  glyceraldehyde-3-phosphate dehydrogenase; oxidoreductase 
A)  phosphoglycerate kinase; transferase 
B)  hexokinase; transferase 
C)  phosphofructokinase; transferase 
D)  glucokinase; transferase 
E)  glyceraldehyde-3-phosphate dehydrogenase; oxidoreductase

Question 6

All are characteristics of Type 1 diabetes mellitus EXCEPT:

Accepted Answer

A)  low levels of glucokinase. 
B)  glucokinase is induced. 
C)  insufficient insulin is produced. 
D)  production of little liver glycogen. 
E)  all are true. 
A)  low levels of glucokinase. 
B)  glucokinase is induced. 
C)  insufficient insulin is produced. 
D)  production of little liver glycogen. 
E)  all are true.

Question 7

Adenylate kinase catalyzes the reaction:
ADP + ____ ⇔ ____ + AMP

Accepted Answer

A)  AMP; Pi 
B)  ADP; ADP 
C)  ADP; ATP 
D)  ATP; ADP 
E)  AMP; ATP 
A)  AMP; Pi 
B)  ADP; ADP 
C)  ADP; ATP 
D)  ATP; ADP 
E)  AMP; ATP

Question 8

AMP is often used in the cytosol as an indicator of low cellular energy. Which of the following enzymes would be activated by AMP?

Accepted Answer

A)  hexokinase 
B)  phosphoglycerate kinase 
C)  phosphofructokinase-1 
D)  glyceraldehyde-3-phosphate dehydrogenase 
E)  both A and C are correct 
A)  hexokinase 
B)  phosphoglycerate kinase 
C)  phosphofructokinase-1 
D)  glyceraldehyde-3-phosphate dehydrogenase 
E)  both A and C are correct

Question 9

A mutase catalyzes which of the reactions, and belongs to which class of enzymes?

Accepted Answer

A)  2-phosphoglycerate ⇔ phosphoenolpyruvate + H2O; lyase 
B)  pyruvate + NADH + H+ ⇔ lactate + NAD+; oxidoreductase 
C)  3-phosphoglycerate ⇔ 2-phosphoglycerate; isomerase 
D)  dihydroxyacetone phosphate ⇔ glyceraldehyde-3-phosphate; isomerase 
E)  glucose-6-phosphate ⇔ fructose-6-phosphate; isomerase 
A)  2-phosphoglycerate ⇔ phosphoenolpyruvate + H2O; lyase 
B)  pyruvate + NADH + H+ ⇔ lactate + NAD+; oxidoreductase 
C)  3-phosphoglycerate ⇔ 2-phosphoglycerate; isomerase 
D)  dihydroxyacetone phosphate ⇔ glyceraldehyde-3-phosphate; isomerase 
E)  glucose-6-phosphate ⇔ fructose-6-phosphate; isomerase

Question 10

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

Accepted Answer

A)  phosphofructokinase-1 
B)  aldolase 
C)  pyruvate kinase 
D)  glucokinase 
E)  none of the above 
A)  phosphofructokinase-1 
B)  aldolase 
C)  pyruvate kinase 
D)  glucokinase 
E)  none of the above

Question 11

Seven of the ten reactions of glycolysis are reversible (ΔG near zero) and can be used in reverse of glycolysis for gluconeogenesis. The three irreversible reactions are catalyzed by:

Accepted Answer

A)  hexokinase, phosphoglycerate kinase, pyruvate kinase. 
B)  triose phosphate isomerase, phosphoglycerate mutase, pyruvate kinase. 
C)  enolase, phosphoglycerate kinase, phosphofructokinase-1. 
D)  hexokinase, phosphoglucoisomerase, glyceraldehyde-3-phosphate dehydrogenase. 
E)  hexokinase, phosphofructokinase-1, pyruvate kinase. 
A)  hexokinase, phosphoglycerate kinase, pyruvate kinase. 
B)  triose phosphate isomerase, phosphoglycerate mutase, pyruvate kinase. 
C)  enolase, phosphoglycerate kinase, phosphofructokinase-1. 
D)  hexokinase, phosphoglucoisomerase, glyceraldehyde-3-phosphate dehydrogenase. 
E)  hexokinase, phosphofructokinase-1, pyruvate kinase.

Question 12

All of the following characterize phosphofructokinase-1 (PFK-1) EXCEPT:

Accepted Answer

A)  the most important regulatory site in glycolysis. 
B)  ATP increases the affinity of the enzyme for fructose-6-phosphate. 
C)  PFK-1 activity is a function of the energy charge of the cell. 
D)  AMP decreases the Km of PFK-1 for fructose-6-phosphate. 
E)  the subunits of PFK-1 behave cooperatively. 
A)  the most important regulatory site in glycolysis. 
B)  ATP increases the affinity of the enzyme for fructose-6-phosphate. 
C)  PFK-1 activity is a function of the energy charge of the cell. 
D)  AMP decreases the Km of PFK-1 for fructose-6-phosphate. 
E)  the subunits of PFK-1 behave cooperatively.

Question 13

The high free energy change for the conversion of PEP to pyruvate is due largely to the ____ conversion of the relatively unstable ____ tautomer of pyruvate to the more stable ____ form following the phosphoryl group transfer step.

Accepted Answer

A)  unfavorable; enol; keto 
B)  unfavorable; keto; aldol 
C)  favorable; keto; enol 
D)  favorable; enol; keto 
E)  favorable; enol; aldol 
A)  unfavorable; enol; keto 
B)  unfavorable; keto; aldol 
C)  favorable; keto; enol 
D)  favorable; enol; keto 
E)  favorable; enol; aldol

Question 14

Lactate produced by anaerobic muscle tissue is:

Accepted Answer

A)  stored in muscle until oxygen is available. 
B)  carried by the blood to the liver for gluconeogenesis and converted to glucose. 
C)  further reduced to glycerol in muscle. 
D)  transferred to erythrocytes to release oxygen from hemoglobin. 
E)  none of the above. 
A)  stored in muscle until oxygen is available. 
B)  carried by the blood to the liver for gluconeogenesis and converted to glucose. 
C)  further reduced to glycerol in muscle. 
D)  transferred to erythrocytes to release oxygen from hemoglobin. 
E)  none of the above.

Question 15

Which of the following amino acids provides the nucleophile in the reaction of class I aldolase?

Accepted Answer

A)  Lys 
B)  Cys 
C)  Ser 
D)  Glu 
E)  His 
A)  Lys 
B)  Cys 
C)  Ser 
D)  Glu 
E)  His

Question 16

When phosphoglucoisomerase is secreted by T-cells it:

Accepted Answer

A)  phosphorylates galactose. 
B)  isomerizes galactose-6-phosphate to glucose-6-phosphate. 
C)  promotes the survival of certain spinal neurons and sensory nerves. 
D)  glycosylates sphingolipids surrounding nerves. 
E)  none of the above. 
A)  phosphorylates galactose. 
B)  isomerizes galactose-6-phosphate to glucose-6-phosphate. 
C)  promotes the survival of certain spinal neurons and sensory nerves. 
D)  glycosylates sphingolipids surrounding nerves. 
E)  none of the above.

Question 17

Discuss the catabolism of fructose in the liver during the glycolytic pathway.​

Accepted Answer

​
In the liver, fructose is phosphorylat

Question 18

Discuss the regulation of pyruvate kinase.​

Accepted Answer

Pyruvate kinase, which mediates the tran

Question 19

All are characteristic of fructose bisphosphate aldolase in animal tissues EXCEPT:

Accepted Answer

A)  It belongs to the lyase class of enzymes. 
B)  The reaction is reversible in erythrocytes (ΔG is very small). 
C)  It is a Class II aldolase. 
D)  The mechanism involves formation of a Schiff base with an active-site lysine side-chain. 
E)  The products are an aldotriose phosphate and a ketotriose phosphate. 
A)  It belongs to the lyase class of enzymes. 
B)  The reaction is reversible in erythrocytes (ΔG is very small). 
C)  It is a Class II aldolase. 
D)  The mechanism involves formation of a Schiff base with an active-site lysine side-chain. 
E)  The products are an aldotriose phosphate and a ketotriose phosphate.

Question 20

The first intermediate of glycolysis with free energy of hydrolysis more negative than that of ATP is:

Accepted Answer

A)  glucose-6-phosphate. 
B)  fructose-6-phosphate. 
C)  fructose-1,6-bisphosphate. 
D)  dihydroxyacetone phosphate. 
E)  1,3-bisphosphoglycerate. 
A)  glucose-6-phosphate. 
B)  fructose-6-phosphate. 
C)  fructose-1,6-bisphosphate. 
D)  dihydroxyacetone phosphate. 
E)  1,3-bisphosphoglycerate.

Exam 18: Glycolysis

In the second half of the glycolytic pathway, ____ ATP molecules are produced and with the offset of ____ ATPs consumed in the first half, the net yield is ____ ATPs per glucose.

α-D-Glucose + ATP → ____ + ____ + H+

The rare hereditary galactosemia involves defects in:

Glyceraldehyde-3-phosphate dehydrogenase belongs to what class of enzymes?

Substrate-level phosphorylation occurs in glycolysis in the reaction catalyzed by ____ and belongs to ____ class of enzymes.

All are characteristics of Type 1 diabetes mellitus EXCEPT:

Adenylate kinase catalyzes the reaction: ADP + ____ ⇔ ____ + AMP

AMP is often used in the cytosol as an indicator of low cellular energy. Which of the following enzymes would be activated by AMP?

A mutase catalyzes which of the reactions, and belongs to which class of enzymes?

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

Seven of the ten reactions of glycolysis are reversible (ΔG near zero) and can be used in reverse of glycolysis for gluconeogenesis. The three irreversible reactions are catalyzed by:

All of the following characterize phosphofructokinase-1 (PFK-1) EXCEPT:

The high free energy change for the conversion of PEP to pyruvate is due largely to the ____ conversion of the relatively unstable ____ tautomer of pyruvate to the more stable ____ form following the phosphoryl group transfer step.

Lactate produced by anaerobic muscle tissue is:

Which of the following amino acids provides the nucleophile in the reaction of class I aldolase?

When phosphoglucoisomerase is secreted by T-cells it:

Discuss the catabolism of fructose in the liver during the glycolytic pathway.​

Discuss the regulation of pyruvate kinase.​

All are characteristic of fructose bisphosphate aldolase in animal tissues EXCEPT:

The first intermediate of glycolysis with free energy of hydrolysis more negative than that of ATP is:

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In the second half of the glycolytic pathway, ATP molecules are produced and with the offset of ATPs consumed in the first half, the net yield is ATPs per glucose.

α-D-Glucose + ATP → + + H⁺

Substrate-level phosphorylation occurs in glycolysis in the reaction catalyzed by and belongs to class of enzymes.

Adenylate kinase catalyzes the reaction: ADP + ⇔ + AMP

The high free energy change for the conversion of PEP to pyruvate is due largely to the conversion of the relatively unstable tautomer of pyruvate to the more stable form following the phosphoryl group transfer step.

Discuss the catabolism of fructose in the liver during the glycolytic pathway.

Discuss the regulation of pyruvate kinase.