Question 1

If glucose was labeled with 14C at carbon #6, what carbon of pyruvate would have the 14C?

Accepted Answer

A)  carboxyl carbon 
B)  ketone carbon 
C)  methyl carbon 
D)  the 14C would be lost as CO2 
E)  the 14C could be present at any of the carbons of pyruvate 
A)  carboxyl carbon 
B)  ketone carbon 
C)  methyl carbon 
D)  the 14C would be lost as CO2 
E)  the 14C could be present at any of the carbons of pyruvate

Question 2

Hexokinase and glucokinase belong to the kinase subclass of what class of enzymes?

Accepted Answer

A)  oxidoreductase 
B)  isomerase 
C)  transferase 
D)  hydrolase 
E)  lyase 
A)  oxidoreductase 
B)  isomerase 
C)  transferase 
D)  hydrolase 
E)  lyase

Question 3

The oxidation of one mole of glucose by anaerobic glycolysis yields a net of:

Accepted Answer

A)  two moles of lactate and two moles of ATP. 
B)  two moles of lactate, two moles of NADH, and two moles of ATP. 
C)  two moles of lactate and six moles of ATP. 
D)  two moles of pyruvate and two moles of ATP. 
E)  two moles of pyruvate, two moles of NADH, and four moles of ATP. 
A)  two moles of lactate and two moles of ATP. 
B)  two moles of lactate, two moles of NADH, and two moles of ATP. 
C)  two moles of lactate and six moles of ATP. 
D)  two moles of pyruvate and two moles of ATP. 
E)  two moles of pyruvate, two moles of NADH, and four moles of ATP.

Question 4

Hormones such as glucagon ____ glycolysis by activating cAMP-dependent protein kinase that will ____ pyruvate kinase to ____ the enzyme.

Accepted Answer

A)  activate; carboxylate; activate 
B)  activate; phosphorylate; activate 
C)  activate; phosphorylate; inhibit 
D)  inhibit; phosphorylate; inhibit 
E)  inhibit; phosphorylate; activate 
A)  activate; carboxylate; activate 
B)  activate; phosphorylate; activate 
C)  activate; phosphorylate; inhibit 
D)  inhibit; phosphorylate; inhibit 
E)  inhibit; phosphorylate; activate

Question 5

Which of the following statements is correct regarding sugar metabolism?

Accepted Answer

A)  lactase, a β-galactosidase type enzyme, cleaves the β(1,4) glycosidic bond observed in lactose 
B)  in the liver, fructose is converted to fructose-1-P, then to dihydroxyacetone and glyceraldehyde-3-phosphate, thus skipping normal glycolytic regulation 
C)  in the muscle, fructose is converted into fructose-1-P by hexokinase 
D)  galactose enters glycolysis as galactose-6-P since the stereochemistry at C-4 is not critical for the first few enzymes of glycolysis 
E)  None of the above are correct 
A)  lactase, a β-galactosidase type enzyme, cleaves the β(1,4) glycosidic bond observed in lactose 
B)  in the liver, fructose is converted to fructose-1-P, then to dihydroxyacetone and glyceraldehyde-3-phosphate, thus skipping normal glycolytic regulation 
C)  in the muscle, fructose is converted into fructose-1-P by hexokinase 
D)  galactose enters glycolysis as galactose-6-P since the stereochemistry at C-4 is not critical for the first few enzymes of glycolysis 
E)  None of the above are correct

Question 6

All are characteristic of the conversion of glucose to lactate EXCEPT:

Accepted Answer

A)  anaerobic pathway with no net oxidation. 
B)  "primed" by ATP phosphorylation. 
C)  located in the cytosol. 
D)  approximately 50% efficient in erythrocytes. 
E)  net production of four ATP per glucose. 
A)  anaerobic pathway with no net oxidation. 
B)  "primed" by ATP phosphorylation. 
C)  located in the cytosol. 
D)  approximately 50% efficient in erythrocytes. 
E)  net production of four ATP per glucose.

Question 7

Which of the following enzymes is NOT used when fructose is metabolized to pyruvate in the liver?

Accepted Answer

A)  triose phosphate isomerase 
B)  glyceraldehyde-3-phospate dehydrogenase 
C)  glucokinase 
D)  phosphofructokinase-1 
E)  pyruvate kinase 
A)  triose phosphate isomerase 
B)  glyceraldehyde-3-phospate dehydrogenase 
C)  glucokinase 
D)  phosphofructokinase-1 
E)  pyruvate kinase

Question 8

All are characteristics of the phosphofructokinase-1 catalyzed reaction EXCEPT:

Accepted Answer

A)  exergonic. 
B)  "priming reaction". 
C)  "valve" controlling the rate of glycolysis. 
D)  commits the cell to metabolize glucose. 
E)  all are true. 
A)  exergonic. 
B)  "priming reaction". 
C)  "valve" controlling the rate of glycolysis. 
D)  commits the cell to metabolize glucose. 
E)  all are true.

Question 9

All are true for 2,3-bisphosphoglycerate (2,3-BPG) EXCEPT:

Accepted Answer

A)  erythrocytes typically have high levels of 2,3-BPG. 
B)  2,3-BPG is synthesized from 1,3-BPG. 
C)  a kinase converts 2,3-BPG to 3-phosphoglycerate. 
D)  2,3-BPG is involved in unloading oxygen from hemoglobin. 
E)  bisphosphoglycerate mutase is an isomerase. 
A)  erythrocytes typically have high levels of 2,3-BPG. 
B)  2,3-BPG is synthesized from 1,3-BPG. 
C)  a kinase converts 2,3-BPG to 3-phosphoglycerate. 
D)  2,3-BPG is involved in unloading oxygen from hemoglobin. 
E)  bisphosphoglycerate mutase is an isomerase.

Question 10

Lactose intolerance is a deficiency of the enzyme ____ that results in the metabolism of lactose by ____.

Accepted Answer

A)  lactose synthase; intestinal enzymes 
B)  lactase; intestinal bacteria 
C)  lactase; intestinal viruses 
D)  β-galactosidase; α-amylase 
E)  none of the above 
A)  lactose synthase; intestinal enzymes 
B)  lactase; intestinal bacteria 
C)  lactase; intestinal viruses 
D)  β-galactosidase; α-amylase 
E)  none of the above

Question 11

The reaction mechanism for glyceraldehyde-3-phosphate dehydrogenase involves ____ attack by a cysteine -SH group on the ____ carbon of the substrate to form a hemithioacetal.

Accepted Answer

A)  electrophilic; carbonyl 
B)  electrophilic; acidic 
C)  nucleophilic; amino 
D)  nucleophilic; carbonyl 
E)  SN2 ; amino 
A)  electrophilic; carbonyl 
B)  electrophilic; acidic 
C)  nucleophilic; amino 
D)  nucleophilic; carbonyl 
E)  SN2 ; amino

Question 12

Under anaerobic conditions, skeletal muscle generates lactate from pyruvate to:

Accepted Answer

A)  lower the pH. 
B)  promote release of oxygen from hemoglobin. 
C)  generate additional ATP. 
D)  be warning of muscle fatigue. 
E)  regenerate NAD+ for further glycolysis. 
A)  lower the pH. 
B)  promote release of oxygen from hemoglobin. 
C)  generate additional ATP. 
D)  be warning of muscle fatigue. 
E)  regenerate NAD+ for further glycolysis.

Question 13

Fructose in the diet or fructose from sucrose in the diet can be a source of calories for fat synthesis in the liver because:

Accepted Answer

A)  ketoses are fattening 
B)  fructose enters glycolysis after the primary regulation point, PFK-1 
C)  fructose provides a net of four ATP from glycolysis 
D)  fructose enters the branch of glycolysis that forms fat 
E)  glycerol (the "backbone" of triacylglycerols) comes specifically from fructose 
A)  ketoses are fattening 
B)  fructose enters glycolysis after the primary regulation point, PFK-1 
C)  fructose provides a net of four ATP from glycolysis 
D)  fructose enters the branch of glycolysis that forms fat 
E)  glycerol (the "backbone" of triacylglycerols) comes specifically from fructose

Question 14

Which of the following pathways is NOT properly paired with its precursor?

Accepted Answer

A)  glycogen synthesis: glucose-1-phosphate 
B)  pentose phosphate pathway: glucose-6-phosphate 
C)  glucosamine-6-phosphate: glucose-6-phosphate 
D)  glucuronic acid: glucose-6-phosphate 
E)  all are correctly paired 
A)  glycogen synthesis: glucose-1-phosphate 
B)  pentose phosphate pathway: glucose-6-phosphate 
C)  glucosamine-6-phosphate: glucose-6-phosphate 
D)  glucuronic acid: glucose-6-phosphate 
E)  all are correctly paired

Question 15

Explain the reaction catalyzed by triose phosphate isomerase in the first phase of gylcolysis.​

Accepted Answer

The aldolase reaction produces two produ

Question 16

For the first five steps of glycolysis, the appropriate sequence of enzymes is:
A.phosphofructokinase-1 (PFK-1).
B.hexokinase / glucokinasE.
C.fructose bisphosphate aldolasE.
D.PhosphoglucoisomerasE.
E.triose phosphate isomerase (TPI).

Accepted Answer

A)  A, C, B, E, D 
B)  B, C, D, E, A 
C)  B, D, C, A, E 
D)  D, B, A, C, E 
E)  B, D, E, C, A 
A)  A, C, B, E, D 
B)  B, C, D, E, A 
C)  B, D, C, A, E 
D)  D, B, A, C, E 
E)  B, D, E, C, A

Question 17

Compare the G values of different steps of the glycolytic pathway and the consequences of the inhibition of these steps.​

Accepted Answer

For reactions 2 and 4 through 9 of glyco

Question 18

Discuss the fate of pyruvate.​

Accepted Answer

The product of glycolysis-pyruvate-is a

Question 19

UDP-galactose is converted to UDP-glucose by the enzyme:

Accepted Answer

A)  galactokinase. 
B)  galactose-uridylyltransferase. 
C)  Phosphoglucomutase. 
D)  UDP-glucose-4-epimerase. 
E)  UDP-galactose-2-epimerase. 
A)  galactokinase. 
B)  galactose-uridylyltransferase. 
C)  Phosphoglucomutase. 
D)  UDP-glucose-4-epimerase. 
E)  UDP-galactose-2-epimerase.

Question 20

Which of the following enzymes is inhibited by phosphorylation?

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

Exam 18: Glycolysis

If glucose was labeled with 14C at carbon #6, what carbon of pyruvate would have the 14C?

Hexokinase and glucokinase belong to the kinase subclass of what class of enzymes?

The oxidation of one mole of glucose by anaerobic glycolysis yields a net of:

Hormones such as glucagon ____ glycolysis by activating cAMP-dependent protein kinase that will ____ pyruvate kinase to ____ the enzyme.

Which of the following statements is correct regarding sugar metabolism?

All are characteristic of the conversion of glucose to lactate EXCEPT:

Which of the following enzymes is NOT used when fructose is metabolized to pyruvate in the liver?

All are characteristics of the phosphofructokinase-1 catalyzed reaction EXCEPT:

All are true for 2,3-bisphosphoglycerate (2,3-BPG) EXCEPT:

Lactose intolerance is a deficiency of the enzyme ____ that results in the metabolism of lactose by ____.

The reaction mechanism for glyceraldehyde-3-phosphate dehydrogenase involves ____ attack by a cysteine -SH group on the ____ carbon of the substrate to form a hemithioacetal.

Under anaerobic conditions, skeletal muscle generates lactate from pyruvate to:

Fructose in the diet or fructose from sucrose in the diet can be a source of calories for fat synthesis in the liver because:

Which of the following pathways is NOT properly paired with its precursor?

Explain the reaction catalyzed by triose phosphate isomerase in the first phase of gylcolysis.​

For the first five steps of glycolysis, the appropriate sequence of enzymes is: A.phosphofructokinase-1 (PFK-1). B.hexokinase / glucokinasE. C.fructose bisphosphate aldolasE. D.PhosphoglucoisomerasE. E.triose phosphate isomerase (TPI).

Compare the G values of different steps of the glycolytic pathway and the consequences of the inhibition of these steps.​

Discuss the fate of pyruvate.​

UDP-galactose is converted to UDP-glucose by the enzyme:

Which of the following enzymes is inhibited by phosphorylation?

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Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

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Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

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Metabolism: an Overview

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Electron Transport and Oxidative Phosphorylation

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

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Filters

If glucose was labeled with ¹⁴C at carbon #6, what carbon of pyruvate would have the ¹⁴C?

Hormones such as glucagon glycolysis by activating cAMP-dependent protein kinase that will pyruvate kinase to the enzyme.

Lactose intolerance is a deficiency of the enzyme that results in the metabolism of lactose by .

The reaction mechanism for glyceraldehyde-3-phosphate dehydrogenase involves attack by a cysteine -SH group on the carbon of the substrate to form a hemithioacetal.

Explain the reaction catalyzed by triose phosphate isomerase in the first phase of gylcolysis.

Compare the G values of different steps of the glycolytic pathway and the consequences of the inhibition of these steps.

Discuss the fate of pyruvate.