Macronutrients Final Exam

Front 1

True or False. The inner mitochondrial membrane is permeable to most small molecules and ions.

Back 1

False

Front 2

The only Insulin-responsive glucose transporter is

Back 2

GLUT 4

Front 3

Which of the following statements is true concerning the mitochondria?
A. The Malate/aspartate shuttle transports molecules across the outer mitochondrial membrane.
B. Porin creates pores in the inner mitochondrial membrane.
C. The citric acid cycle/Krebs cycle/ TCA cycle is located in the mitochondrial matrix
D. All of the above
E. A and B

Back 3

C. The citric acid cycle/Krebs cycle/ TCA cycle is located in the mitochondrial matrix

Front 4

GLUT 5 transports fructose into cells, but does not transport glucose.
A.True
B.False

Back 4

A. True

Front 5

Which of the following fuels is used by all of the tissues?
A. Branched-chain amino acids
B. Ketones
C. Free Fatty Acids
D. Glucose
E. lactate (lactic acid)

Back 5

D. Glucose

Front 6

Which of the following tissues uses glutamine for fuel?
A. Intestine
B. Kidney
C. Adipose tissue
D. Brain
E. Heart

Back 6

A. Intestine

Front 7

During an energy deficit the adipose tissue will release fatty acids as well as synthesize glycerol for triacylglycerol synthesis; the triacylglycerols to remain in the adipose tissue.
A. True
B. False

Back 7

A. True

Front 8

Glucose is completely oxidized to CO2 and H2O, with the production of ATP, in the red blood cell.
A. True
B. False

Back 8

B. False

Front 9

This tissue releases alanine as a used fuel.
A. Brain
B. Skeletal muscle
C. Red Blood cells
D. Liver
E. Heart

Back 9

B. Skeletal muscle

Front 10

Which of the following glucose transporters is responsible for glucose uptake into the liver and pancreas?
A. GLUT 1
B. GLUT 2
C. GLUT 3
D. GLUT 4
E. GLUT 5

Back 10

B. GLUT 2

Front 11

11. Choose the correct statement concerning glucose transport from the choices below.
A. GLUT 1 and GLUT 3 are high affinity glucose transporters responsible for intestinal glucose transport.
B. Red blood cells transport glucose into the cells via the GLUT 4 glucose transporter.
C. The expression of the gene for GLUT 2 (SLC2A2) in the pancreatic β cell is regulated by blood glucose.
D. All of the above
E. B and C

Back 11

C. The expression of the gene for GLUT 2 (SLC2A2) in the pancreatic β cell is regulated by blood glucose.

Front 12

12. Which of the following conversions from substrate to product produces ATP during glycolysis?
A. glyceraldehyde 3-phosphate 1,3-diphosphoglycerate
B. glucose glucose 6-phosphate
C. 1,3-diphosphoglycerate 3-phosphoglycerate
D. 2-phosphoglycerate phosphoenolpyruvate
E. A and D

Back 12

C. 1,3-diphosphoglycerate 3-phosphoglycerate

Front 13

13. Reducing equivalents produced by glycolysis enter the mitochondria through the malate/aspartate shuttle.
A. True
B. False

Back 13

A. True

Front 14

14. Which of the following substrate product (enzyme) combinations produces reducing equivalents during glycolysis?
A. fructose 6-phosphate fructose 1,6-bisphosphate (phosphfructokinase)
B. phosphoenolpyruvate pyruvate (pyruvate kinase)
C. glucose glucose 6-phosphate (glucokinase)
D. glyceraldehyde 3-phosphate 1,3-diphosphoglycerate (glyceraldehyde 3-phosphate dehydrogenase)
E. fructose 1,6-bisphosphate glyceraldehyde 3-phosphate (aldolase)

Back 14

D. glyceraldehyde 3-phosphate 1,3-diphosphoglycerate (glyceraldehyde 3-phosphate dehydrogenase)

Front 15

15. Which of the following enzymes in glycolysis are inhibited by ATP?
A. phosphfructokinase
B. pyruvate kinase
C. aldolase
D. enolase
E. A and B

Back 15

E. A and B

Front 16

16. Choose the INCORRECT statement.
A. Fructose is metabolized in the liver by essentially entering glycolysis following conversion to glyceraldehyde 3-phosphate.
B. Fructose metabolism is tightly regulated by the activity of phosphofructokinase.
C. Fructokinase phosphorylates fructose to fructose 1-phosphate.
D. All of the statements above are incorrect.
E. All of the statements above are correct.

Back 16

B. Fructose metabolism is tightly regulated by the activity of phosphofructokinase.

Front 17

17. Choose the correct answer concerning glycolysis from the following statements.
A. A six-carbon molecule (glucose) is converted to two three-carbon molecules (pyruvate).
B. A net total of four ATP molecules are produced by glycolysis.
C. The phosphorylation of glucose consumes one molecule of ATP.
D. All of the above
E. B and C

Back 17

E. B and C

Front 18

18. Heavy consumption of fructose can cause the accumulation of acetyl CoA, which is used for fatty acid synthesis, resulting in increased hepatic lipogenesis.
A. True
B. False

Back 18

A. True

Front 19

19. This general type of enzyme is associated with the production of reducing equivalents in glycolysis and the citric acid cycle/Krebs cycle/TCA cycle (NADH) and the pentose phosphate pathway (NADPH).
A. Carboxylase
B. Isomerase
C. Kinase
D. Phosphatase
E. Dehydrogenase

Back 19

E. Dehydrogenase

Front 20

20. In skeletal muscle, fructose is phosphorylated by fructokinase to fructose 1-phosphate, which is converted to glyceraldehyde 3-phosphate and enters glycolysis.
A. True
B. False

Back 20

B. False

Front 21

21. Which substrate product reaction is the first committed step in glycolysis?
A. glucose glucose 6-phosphate
B. fructose 6-phosphate fructose 1,6-bisphosphate
C. fructose 1,6-bisphosphate glyceraldehyde 3-phosphate
D. 3-phosphoglycerate 2-phosphoglycerate
E. phosphoenolpyruvate pyruvate

Back 21

B. fructose 6-phosphate fructose 1,6-bisphosphate

Front 22

22. The second phase of glycolysis – glyceraldehyde 3-phosphate pyruvate – results in the production of reducing equivalents but consumes two molecules of ATP.

A. True
B. False

Back 22

B. False

Front 23

23. Which of the following statements is INCORRECT concerning the Cori Cycle.
A. The Cori Cycle occurs during aerobic conditions.
B. The Cori Cycle connects the liver with the energy needs of skeletal muscle.
C. Skeletal muscle gluconeogenesis provides the energy needs of the muscle during anaerobic conditions.
D. Lactate produced by the muscle is secreted into the blood, taken up by the liver, and used to produce glucose.
E. A and C

Back 23

E. A and C

Front 24

24. Pyruvate is converted to lactate if oxygen is not available.
A. True
B. False

Back 24

A. True

Front 25

25. Galactose is phosphorylated to galactose 1-phosphate by galactokinase.
A. True
B. False

Back 25

A. True

Front 26

26. In which of the following tissues does gluconeogenesis occur?
A. Liver
B. Kidney
C. Skeletal muscle
D. All of the above
E. A and B

Back 26

E. A and B

Front 27

27. Which of the following reactions is part of gluconeogenesis?
A. pyruvate phosphoenolpyruvate (pyruvate kinase)
B. oxaloacetate phosphoenolpyruvate (phosphoenolpyruvate carboxykinase)
C. fructose 6-phosphate glucose 6-phosphate (phosphoglucose isomerase)
D. B and C
E. A and C

Back 27

D. B and C

Front 28

28. Which of the following reactions is part of gluconeogenesis?
A. pyruvate oxaloacetate (pyruvate carboxylase)
B. fructose 1,6-bisphophate fructose 6-phosphate (fructose 1,6-bisphosphatase)
C. glucose 6-phosphate glucose (glucose 6-phosphatase)
D. All of the above.
E. B and C

Back 28

D. All of the above.

Front 29

29. Its activity is coordinated with GLUT 4 activity.
A. Hexokinase
B. Glucokinase

Back 29

A. Hexokinase

Front 30

30. Its synthesis in the liver is regulated by insulin and glucagon.
A. Hexokinase
B. Glucokinase

Back 30

B. Glucokinase

Front 31

31. GLUT 2 activity and the activity of this enzyme are linked.
A. Hexokinase
B. Glucokinase

Back 31

B. Glucokinase

Front 32

32. This enzyme has a high affinity for glucose and is saturated at physiological concentrations of glucose.
A. Hexokinase
B. Glucokinase

Back 32

A. Hexokinase

Front 33

33. Glucose 6-phosphate does not inhibit the activity of this enzyme.
A. Hexokinase
B. Glucokinase

Back 33

B. Glucokinase

Front 34

34. Which of the following statements is true concerning the Glucose-Alanine Cycle?
A. The Glucose-Alanine Cycle occurs during periods of fasting.
B. The main amino acid secreted by the skeletal muscle during fasting is alanine.
C. Alanine secreted by the skeletal muscle is taken up by the liver, undergoes deamination, and enters the gluconeogenesis pathway.
D. All of the above
E. A and C

Back 34

D. All of the above

Front 35

35. The total number of ATP equivalents formed from the complete oxidation of a molecule of glucose from glycolysis citric acid cycle oxidative phosphorylation is 24.
A. True
B. False

Back 35

B. False

Front 36

36. Protons flow through every complex in the electron transport chain but this one.
A. Complex III- Cytochrome C Reductase
B. Complex I - NADH-Q Reductase
C. Complex IV – Cytochrome oxidase
D. Complex II – Succinate-Q Reductase

Back 36

D. Complex II – Succinate-Q Reductase

Front 37

37. Which of the following statements is true concerning electron transport/oxidative phosphorylation?
A. The electron transport enzyme complexes are located in the outer mitochondrial membrane.
B. The large charge difference between across the inner mitochondrial membrane drives the synthesis of ATP.
C. ATP synthesis occurs in the intermembrane space between the inner mitochondrial membrane and the outer mitochondrial membrane.
D. More ATP will be synthesized if electrons enter the electron transport chain at Complex II than at Complex I
E. Synthesized ATP is transported out of the mitochondria through a translocase located in the outer mitochondrial membrane.

Back 37

B. The large charge difference between across the inner mitochondrial membrane drives the synthesis of ATP.

Front 38

38. The condensation of oxaloacetate with acetyl CoA to form citrate is catalyzed by this enzyme.
A. Citrate synthase
B. Aconitase
C. Succinate dehydrogenase
D. Pyruvate dehydrogenase
E. Fumerase

Back 38

A. Citrate synthase

Front 39

39. The conversion of these citric acid cycle substrates to products results in the formation of reducing equivalents in the form of NADH.
A. succinyl CoA succinate
B. isocitrate α-ketoglutarate
C. malate oxaloacetate
D. All of the above
E. B and C

Back 39

E. B and C

Front 40

40. Oxaloacetate readily crosses the inner mitochondrial membrane.
A. True
B. False

Back 40

B. False

Front 41

41. In the electron transport chain, electrons are transferred from NADH to a flavin coenzyme to coenzyme Q (ubiquinone) within this complex.
A. Complex III- Cytochrome C Reductase
B. Complex I - NADH-Q Reductase
C. Complex IV – Cytochrome oxidase
D. Complex II – Succinate-Q Reductase

Back 41

B. Complex I - NADH-Q Reductase

Front 42

42. Electrons from the reduced riboflavin coenzyme, FADH2, enter the electron transport chain at this point.
A. Complex III- Cytochrome C Reductase
B. Complex I - NADH-Q Reductase
C. Complex IV – Cytochrome oxidase
D. Complex II – Succinate-Q Reductase

Back 42

D. Complex II – Succinate-Q Reductase

Front 43

43. The conversion of glucose 6-phosphate to ribulose 5-phosphate in the pentose phosphate pathway is reversible, and will generate glycolytic intermediates.
A. True
B. False

Back 43

B. False

Front 44

44. Which of the following reactions in the citric acid cycle results in the formation of the reduced riboflavin coenzyme?
A. succinate fumarate
B. succinyl CoA succinate
C. fumerate malate
D. citrate isocitrate
E. pyruvate oxaloacetate

Back 44

A. succinate fumarate

Front 45

45. Electrons are transferred to molecular oxygen in the electron transport chain at this point.
A. Complex III- Cytochrome C Reductase
B. Complex I - NADH-Q Reductase
C. Complex IV – Cytochrome oxidase
D. Complex II – Succinate-Q Reductase

Back 45

C. Complex IV – Cytochrome oxidase

Front 46

46. Glycogen is the major form of glucose storage in the body.
A. True
B. False

Back 46

A. True

Front 47

47. AMP (adenosine monophosphate) decreases glycogen phosphorylase activity and inhibits glycogenolysis.
A. True
B. False

Back 47

B. False

Front 48

48. Which of the following statements is true concerning pyruvate dehydrogenase?
A. Pyruvate dehydrogenase catalyzes the oxidative carboxylation of pyruvate to acetyl CoA with the generation of NADH.
B. The pyruvate dehydrogenase complex is located in the outer membrane of the mitochondria.
C. Phosphorylation of one of the subunits of pyruvate dehydrogenase results in its activation.
D. Acetyl CoA feeds back on the enzyme, promoting phosphorylation and increasing its activation.
E. NADH stimulates the activity of pyruvate dehydrogenase.

Back 48

A. Pyruvate dehydrogenase catalyzes the oxidative carboxylation of pyruvate to acetyl CoA with the generation of NADH.

Front 49

49. The coenzymes of the B vitamins, thiamin, riboflavin, and niacin, are necessary for the function of pyruvate dehydrogenase complex.
A. True
B. False

Back 49

A. True

Front 50

50. Which of the following statements is true concerning glycogenesis and glycogenolysis?
A. Insulin dephosphorylates glycogen synthase and glycogen phosphorylase, thus promotes glycogen synthesis.
B. Glucagon and epinephrine cause the phosphorylation of glycogen phosphorylase, activating the enzyme and stimulating glycogenolysis.
C. In muscle, phosphorylase kinase is only fully active when phosphorylated and binding calcium.
D. All of the above
E. A and C

Back 50

D. All of the above

Front 51

51. Which of the following statements is true concerning the pentose phosphate pathway?
A. The oxidative phase of the pathway produces glycolytic intermediates.
B. NADPH synthesis occurs as ribulose 5-phosphate is metabolized through the non-oxidative phase.
C. Because of the reversible reactions in the non-oxidative phase, nucleotide degradation can contribute to glycolysis or gluconeogenesis.
D. A and B
E. B and C

Back 51

C. Because of the reversible reactions in the non-oxidative phase, nucleotide degradation can contribute to glycolysis or gluconeogenesis.

Front 52

1. Which of the following is NOT a component of the promoter region of a gene?
A. 7-methyl guanosine
B. TATA box
C. binding site for RNA polymerase
D. CAAT box

Back 52

A. 7-methyl guanosine

Front 53

2. This amino acid is considered a conditionally essential amino acid.
A. proline
B. histidine
C. leucine
D. serine
E. threonine

Back 53

A. proline

Front 54

3. Beta-oxidation of fatty acids results in the formation of an acetyl CoA.
A. true
B. false

Back 54

A. true

Front 55

4. This enzyme is inhibited by malonyl CoA during beta-oxidation of fatty acids.
A. carnitine palmatoyl transferase II
B. carnitine acylcarnitine translocase
C. carnitine palmitoyl transferase I
D. acyl CoA synthetase
E. A & C

Back 55

C. carnitine palmitoyl transferase I

Front 56

5. Oleyl CoA, with a double bond between carbons 9-10 is completely oxidized to acetyl CoA by beta-oxidation.
A. true
B. false

Back 56

B. false

Front 57

6. This enzyme is associated with the pyruvate/malate cycle and converts citrate to oxaloacetate and acetyl CoA in the cytosol.
A. pyruvate dehydrogenase
B. ATP-citrate lyase
C. citrate synthase
D. pyruvate carboxylase
E. malic enzyme

Back 57

B. ATP-citrate lyase

Front 58

7. Which of the following statements is true concerning fatty acid synthesis?
A. fatty acid synthase contains 4 enzymatic activities.
B. the acyl carrier domain contains a thymidine binding site
C. active fatty acid synthase is a homdimer
D. A & C
E. all of the above

Back 58

D. A & C

Front 59

8. The product of the first reaction in fatty acid synthesis is:
A. acetyl CoA
B. malonyl CoA
C. oxaloacetate
D. glycerol
E. plamitate CoA

Back 59

B. malonyl CoA

Front 60

9. Adenine base pairs with cytosine.
A. true
B. false

Back 60

B. false

Front 61

10. Which of the following amino acids is an essential amino acid?
A. cysteine
B. glutamine
C. alanine
D. methionine
E. tyrosine

Back 61

D. methionine

Front 62

11. The phosphorylation of acetyl CoA carboxylase results in its inactivation.
A. true
B. false

Back 62

A. true

Front 63

12. Which of the following statements is true concerning mRNA synthesis?
A. the pre-mRNA contains a 7 methyl-guanosine cap at its 3’end.
B. a splicesome is responsible for removing introns within the pre-mRNA.
C. polyadenylation occurs at the 3’ end of the pre-mRNA.
D. A & C
E. B & C

Back 63

E. B & C

Front 64

13. During transamination the amino group from cysteine is removed.
A. true
B. false

Back 64

A. true

Front 65

14. Mitochondrial acetyl CoA is used for fatty acid synthesis by condensing with oxaloacetate to form citrate, which is transported across the inner mitochondrial membrane by a tricarboxylate carrier.
A. true
B. false

Back 65

A. true

Front 66

15. mRNA that is transported randomly between the endoplasmic reticulum and the cytosol for translation.
A. true
B. false

Back 66

B. false

Front 67

16. Which of the following statements is true concerning glutamate dehydrogenase and its reaction?
A. it converts a keto acid to an amino acid
B. it produces NADPH
C. it is involved in the deamination of glutamate
D. A & B
E. All of the above

Back 67

E. All of the above

Front 68

17. Elongation reactions for fatty acid synthesis occurs in the cytosol.
A. true
B. false

Back 68

B. false

Front 69

18. In the mitochondria, elongation of fatty acids uses long chain acyl-CoAs as substrates.
A. true
B. false

Back 69

B. false

Front 70

19. Acetylation of histones results in gene activation.
A. true
B. false

Back 70

A. true

Front 71

20. Small nucleolar RNAs (snoRNA)
A. are constituents of the spliceosome
B. are functional enzymes in the splicing reaction.
C. are 22 nucleotides in length
D. cleave pre-ribosomal RNAs into subunits
E. C & D

Back 71

E. C & D

Front 72

21. Small interfering RNAs label specific mRNAs for destruction.
A. true
B. false

Back 72

A. true

Front 73

22. The transfer of the amide group from glutamine to another compound is called:
A. deamidation
B. transmidation
C. transamination

Back 73

B. transmidation

Front 74

23. Which of the following statements is true concerning acetyl CoA carboxylase?
A. AMPK (5’actiaved protein kinase) phosphorylates acetyl CoA carboxylase, resulting in its activation.
B. Glucagon and epinephrine stimulate the activity of acetyl CoA carboxylase.
C. Palmitoyl CoA cause acetyl CoA carboxylase to depolymerize, resulting in its activation
D. None of the statements are true.
E. A & B

Back 74

D. None of the statements are true.

Front 75

24. The conversion of arginine to urea requires this enzyme.
A. amino transferase
B. arginase
C. carbamoyl phosphate synthase 1
D. glutamate dehydrogenase

Back 75

B. arginase

Front 76

25. Fatty acid synthesis requires:
A. NADH
B. NADPH
C. NAD
D. FADH2

Back 76

B. NADPH

Front 77

26. The mature mRNA can be translated in the cytoplasm (cytosol) or the smooth endoplasmic reticulum.
A. true
B. false

Back 77

B. false

Front 78

27. This amino acid does not directly undergo transamination.
A. lysine
B. tryptophan
C. proline
D. A & B
E. All of the above

Back 78

E. All of the above

Front 79

28. When glucose is the primary substrate 60% of the NADPH for fatty acid synthesis comes from the pentose phosphate pathway.
A. true
B. false

Back 79

A. true

Front 80

29. N-acetyl glutamate activates this enzyme.
A. arginosuccinate lyase
B. arginase
C. carbamoyl phosphate synthase 1
D. urease
E. ornithine carbamoyl transferase

Back 80

C. carbamoyl phosphate synthase 1

Front 81

30. Triacylglycerol synthesis is thought to be regulated by ___.
A. the translocation of glycerol 3-phosphate acyl transferase from the cytosol to the smooth endoplasmic reticulum.
B. the translocation of phosphatidic acid phosphatase from the cytosol to the smooth endoplasmic reticulum.
C. increasing the transcription of the glycerol 3-phosphate acyl transferase gene in the fed state.
D. increasing the transcription of the phosphatidic acid phosphatase gene in the fasted state.
E. None of the choices are correct.

Back 81

C. increasing the transcription of the glycerol 3-phosphate acyl transferase gene in the fed state.

Front 82

31. Which position of the triacylglycerol is the last to lose its fatty acid?
A. sn-1
B. sn-2
C. sn-3

Back 82

B. sn-2

Front 83

32. microRNAs are most similar to which small RNA?
A. snoRNA (small nucleolar RNA)
B. siRNA (silencing RNA)
C. snRNA (small nuclear RAN)

Back 83

B. siRNA (silencing RNA)

Front 84

33. Arginine directly stimulates the activity of this enzyme associated with the urea cycle.
A. carbamoyl phosphate synthase 1
B. N-acetyl glutamate synthase
C. arginase
D. aspartate aminotransferase
E. C & D

Back 84

B. N-acetyl glutamate synthase

Front 85

34. Amino acids that are converted to acetoacetate are considered lipogenic because ___.
A. acetoacetate is ultimately converted to pyruvate.
B. acetoacetate is ultimately converted to oxaloacetate.
C. acetoacetate is ultimately converted to acetyl CoA.
D. B & C

Back 85

C. acetoacetate is ultimately converted to acetyl CoA.

Front 86

35. This amino acid is preferentially used by the small intestine.
A. arginine
B. histidine
C. alanine
D. glutamine
E. cysteine

Back 86

D. glutamine

Front 87

36. Amino acid oxidation makes up what percentage of ATP from 1 g of meat?
A. 35%
B. 5%
C. 60%

Back 87

A. 35%

Front 88

37. How does insulin affect lipolysis?
A. it stimulates lipolysis.
B. it inhibits adenylate cyclase
C. it simulates protein kinase A-dependent phosphorylation.
D. it stimulates the activity of hormone-sensitive lipase.
E. A & B

Back 88

B. it inhibits adenylate cyclase

Front 89

38. Which of the following statements is true concerning lipolysis?
A. During basal lipolysis fatty acids are reesterified to glycerol to form triacylglycerol.
B. During stimulated lipolysis, CGI-58 is dephosphorylated and associates with Perilipin A.
C. Phosphorylated adipose triglyceride lipase associates with phosphorylated hormone sensitive lipase during basal lipolysis.
D. B & C
E. All of the above

Back 89

A. During basal lipolysis fatty acids are reesterified to glycerol to form triacylglycerol.

Front 90

39. A protein that acquires a single ubiquitin molecule will be degraded in the proteasome.
A. true
B. false

Back 90

B. false

Front 91

40. Which of the follow statements is FALSE concerning protein degradation?
A. Ubiquitin is activated by the ubiquitin conjugating enzyme.
B. Ubiquitin protein ligase is responsible for transferring ubiquitin to a carrier protein.
C. The successive conjugation of ubiquitin moieties generates a polyubiquitin chain that functions as a signal to target the protein substrate to the 26S proteasome for degradation.
D. A & B
E. All of the above

Back 91

D. A & B

Front 92

41. Protein degradation is stimulated with a high glucagon to insulin ratio.
A. true
B. false

Back 92

A. true

Front 93

42. A high insulin to glucagon ratio will stimulate amino acid-dependent gluconeogenesis in the liver.
A. true
B. false

Back 93

B. false

Front 94

43. How many ATP are consumed by the urea cycle?
A. 3
B. 2
C. 1

Back 94

A. 3

Front 95

44. Long-term regulation of the urea cycle occurs.
A. with the synthesis of N-acetyl-glutamate.
B. increased synthesis of the urea cycle enzymes.
C. increased synthesis the transaminases.

Back 95

B. increased synthesis of the urea cycle enzymes.

Front 96

45. This enzyme is involved in the first committed step in triacylglycerol synthesis.
A. fatty acyl CoA synthetase
B. glycerol 3-phosphate dehydrogenase
C. acyltransferase
D. glycerol kinase
E. glycerol 3-phosphate acyltransferase

Back 96

E. glycerol 3-phosphate acyltransferase

Front 97

46. Which position of the glycerol backbone is first populated by a fatty acid?
A. sn-1
B. sn-2
C. sn-3

Back 97

A. sn-1

Front 98

47. Choose the INCORRECT statement concerning beta-oxidation from the following choices.
A. Four different FAD-dependent acyl CoA dehydrogenases catalyze the first step of beta-oxidation for long-chain, medium-chain, or short-chain fatty acids.
B. NADPH is a necessary electron donor in the function of the second oxidation step in the beta-oxidation of saturated fatty acids.
C. A tri-functional protein is responsible for the last three enzymatic reactions of hydration, oxidation, and cleavage for beta-oxidation of saturated fatty acids.
D. Linoleoyl-CoA, which has double bonds between carbons 9-10 and 12-13, initially undergoes three rounds of beta-oxidation before additional enzymatic steps are required.
E. B & D

Back 98

B. NADPH is a necessary electron donor in the function of the second oxidation step in the beta-oxidation of saturated fatty acids.

Front 99

48. Glycerol released from fat can be used by the muscle as a fuel source.
A. true
B. false

Back 99

A. true

Front 100

49. The 20S core particle of the proteasome is responsible for recognizing the polyubiquitin tail of targeted proteins.
A. true
B. false

Back 100

B. false

Front 101

50. Choose the correct statement concerning carnitine palmitoyl transferase II.
A. Carnitine palmitoyl transferase II is located in the inner mitochondrial membrane.
B. Carnitine palmitoyl transferase II catalyzes fatty acid fatty acyl CoA.
C. Carnitine palmitoyl transferase II transports acylcarnitine into the mitochondrial matrix.
D. Carnitine palmitoyl transferase II is inhibited by the final product of fatty acid synthesis, palmitate.
E. Carnitine palmitoyl transferase II is inhibited by malonyl CoA.

Back 101

A. Carnitine palmitoyl transferase II is located in the inner mitochondrial membrane.

Front 102

51. One function of the 19S regulatory particle of the proteasome is to unfold substrates.
A. true
B. false

Back 102

A. true

Front 103

1. Where within the gastrointestinal tract does mechanical digestion occur?
A. Duodenum
B. Esophagus
C. Ascending colon
D. Stomach

Back 103

D. Stomach

Front 104

2. Increasing the surface area is a basic concept associated with digestion and absorption. Which of the following statements below are examples of this basic concept?
A. The length of the small intestine is 5 to 7 cm in length.
B. The jejunum contains large, circular folds called plicae cirulares.
C. The plasma membrane which makes up the apical side of the intestinal cells (enterocytes) contains microvilli.
D. All of the above
E. A and B

Back 104

D. All of the above

Front 105

3. The chief cells of the gastric pits of the stomach secrete HCl and intrinsic factor.
A. True
B. False

Back 105

B. False

Front 106

4. Which of the following enzymes is a trypsin activator in the small intestine?
A. carboxypeptidase A
B. enterokinase
C. pepsinogen
D. peptidyl dipeptidase
E. elastase

Back 106

B. enterokinase

Front 107

5. Which of the following statements is correct?
A. The acidic chyme entering the duodenum from the stomach stimulates the release of secretin.
B. Cholecystokinin (CCK) stimulates the pancreas to release bicarbonate-rich juice into the duodenum.
C. The Brunners glands in the small intestine release cholecystokinin.
D. All of the above
E. A and B

Back 107

A. The acidic chyme entering the duodenum from the stomach stimulates the release of secretin.

Front 108

6. This dietary fiber contains linear unbranched polymers of β-D-glucose with mixed glycosidic linkages.
A. β-glucans
B. chitosan
C. cellulose
D. gums
E. pectins

Back 108

A. β-glucans

Front 109

7. Which of the following is FALSE regarding endopeptidase?
A. It is a pepsin that is active in the gastric phase of digestion
B. It functions by hydrolyzing external peptide bonds
C. It breaks peptides into smaller fragments
D. All of the above
E. A and C

Back 109

B. It functions by hydrolyzing external peptide bonds

Front 110

Why are zymogens secreted from the pancreas rather than active enzymes?
A. Active enzymes would be too large to fit through the pancreatic duct
B. Active enzymes cannot stay active long enough to reach the small intestine
C. Active enzymes would cause damage to the pancreas and pancreatic duct

Back 110

C. Active enzymes would cause damage to the pancreas and pancreatic duct

Front 111

Fermentation products of dietary fiber can be used by tissues in the body for energy.
A. True
B. False

Back 111

A. True

Front 112

Dipeptides and tripeptides are absorbed more efficiently and effectively that free amino acids.
A. True
B. False

Back 112

A. True

Front 113

Facilitated diffusion requires the hydrolysis of ATP.
A. True
B. False

Back 113

B. False

Front 114

Which of the following statements is correct?
A. The liver synthesizes bile.
B. The pancreas secretes both enzymes and hormones.
C. The goblet cells of the small intestinal epithelium secrete secretin to contract the gallbladder and release bile.
D. All of the above
E. A and B

Back 114

E. A and B

Front 115

Protein sources include which of the following
A. Diet
B. Sloughed intestinal cells
C. Pancreatic enzymes
D. A and B
E. All of the above

Back 115

E. All of the above

Front 116

Chemical digestion in the oral cavity includes which of the following?
A. Grinding or cutting to form food bolus
B. Salivary lubrication of food bolus for swallowing
C. Salivary amylase for starch digestion
D. Salivary lipase for fat digestion
E. All of the above

Back 116

C. Salivary amylase for starch digestion

Front 117

Where are most nutrients absorbed?
A. Stomach
B. Duodenum
C. Jejunum
D. Ileum
E. Large intestine

Back 117

C. Jejunum

Front 118

16. Secretion of bicarbonate by the pancreas raises the pH of chyme in the small intestine to the optimal pH for pancreatic proteases. What is the optimal pH for pancreatic proteases?
A. 3-4
B. 4-5
C. 5-6
D. 6-7
E. 7-8

Back 118

D. 6-7

Front 119

Which section of the gastrointestinal tract contains enterokinase?
A. Duodenum
B. Ileum
C. Transverse colon
D. Stomach
E. Esophagus

Back 119

A. Duodenum

Front 120

Which of the following statements is true concerning proteolytic enzymes in the small intestine?
A. Pepsinogen secreted in the ileum is activated by enterokinase.
B. Trypsin cleaves (hydrolyzes) zymogens resulting in their activation in the intestinal lumen.
C. Carboxypeptidase A and B cleaves (hydrolyzes) internal peptide bonds within polypeptides in the lumen of the small intestine.
D. All of the above
E. A and B

Back 120

B. Trypsin cleaves (hydrolyzes) zymogens resulting in their activation in the intestinal lumen.

Front 121

Oligopeptides are transported into the enterocyte, reconstituted to their respective polypeptides in the endoplasmic reticulum, and transported across the basolateral membrane through specific transporters.
A. True
B. False

Back 121

B. False

Front 122

20. The products of this enzyme are fatty acids and 2-monoacylglycerols.
A. carboxylester lipase
B. pancreatic lipase
C. phospholipase A2

Back 122

B. pancreatic lipase

Front 123

21. Which is false regarding a mixed micelle?
A. It contains cholesterol and bile salts
B. The hydrophobic ends of components extend toward the center
C. Triacylglyceral (TAG) is the main component
D. All of the above are true

Back 123

C. Triacylglyceral (TAG) is the main component

Front 124

Colipase is necessary because bile acids inhibit pancreatic lipase unless colipase is present at the lipid-aqueous interface.
A. True
B. False

Back 124

A. True

Front 125

Which is FALSE regarding carboxylester lipase?
A. Activity is stimulated by bile acids
B. Secreted as an inactive enzyme
C. Hydrolyzes cholesteryl esters to free cholesterol and fatty acid
D. Hydrolyses triacylglycerols at all positions
E. All of the above are true

Back 125

B. Secreted as an inactive enzyme

Front 126

Which is NOT a function of the large intestine?
A. Nutrient breakdown by brush border enzymes
B. Absorption of water and electrolytes
C. Microbial fermentation
D. Formation/storage of feces
E. All of the above are functions of the large intestine

Back 126

A. Nutrient breakdown by brush border enzymes

Front 127

Peristalsis is the term for rhythmic contractions of the esophagus to facilitate the movement of the food bolus to the stomach.
A. True
B. False

Back 127

A. True

Front 128

Pancreatic α-amylase allows humans to partially digest hemicellulose because the enzyme cleaves the β(1,4) glycosidic linkages.
A. True
B. False

Back 128

B. False

Front 129

One of the functions of this portion of the gastrointestinal tract is absorption of water and electrolytes.
A. mouth
B. large intestine
C. esophagus
D. rectum
E. small intestine

Back 129

B. large intestine

Front 130

Fatty acid translocase (CD36):
A. Translocates short-chain fatty acids across the basolateral membrane of the enterocyte
B. Translocates long-chain fatty acids across the basolateral membrane of the enterocyte
C. Translocates short-chain fatty acids across the apical membrane of the enterocyte
D. Translocates long-chain fatty acids across the apical membrane of the enterocyte

Back 130

D. Translocates long-chain fatty acids across the apical membrane of the enterocyte

Front 131

Fatty acid-binding proteins transport lipids to the _____________ to be reesterified.
A. Nucleus
B. Golgi apparatus
C. Mitochondria
D. Ribosomes
E. Endoplasmic reticulum

Back 131

E. Endoplasmic reticulum

Front 132

The brush border enzyme isomaltase cleaves the α(1,6) glycosidic bonds of α dextrins.
A. True
B. False

Back 132

A. True

Front 133

Which of the following statements is true concerning fructose transport into the enterocyte?
A. GLUT 2 is the brush border transport protein responsible for fructose transport into the enterocyte.
B. The fructose transporter at the brush border is GLUT 5.
C. Secondary active transport is the mechanism fructose utilizes to cross the brush border into the enterocyte.
D. Fructose is transported into the enterocyte via the SGLT-1 transporter.
E. C and D

Back 133

B. The fructose transporter at the brush border is GLUT 5.

Front 134

Which is false regarding amylase?
A. Produced by and secreted from the salivary and pancreas exocrine glands
B. Salivary α-amylase begins digestion of carbohydrate in the oral cavity
C. α(1,4) endoglucosidase cleaves internal glycosidic bonds resulting in glucose polymers
D. Pancreatic α-amylase cleaves starch into the final oligosaccharide products in the duodenum
E. All of the above are true

Back 134

E. All of the above are true

Front 135

The two oligosaccharidases with independent domains that complete carbohydrate digestion at the brush border membrane surface are __________ and __________.
A. Maltase-glucoamylase and Sucrase-isomaltase
B. Fructase-glucoamylase and Lactase-isomaltase

Back 135

A. Maltase-glucoamylase and Sucrase-isomaltase

Front 136

Digestion of the disaccharide sucrose yields which monosaccarides?
A. Fructose and galactose
B. Glucose and fructose
C. Galactose and glucose
D. None of the above

Back 136

B. Glucose and fructose

Front 137

Which of the following transporters function through secondary active transport?
A. GLUT 2
B. fatty acid translocase (CD36)
C. sodium glucose transporter 1 (SGLT1)
D. Newman-Pick C1 like 1
E. GLUT 5

Back 137

C. sodium glucose transporter 1 (SGLT1)

Front 138

This transporter primarily transports cholesterol into the enterocyte.
A. Fatty acid translocase
B. Newman-Pick C1 like 1
C. ATP-binding cassette transporters

Back 138

B. Newman-Pick C1 like 1

Front 139

This enzyme hydrolyzes the fatty acid from the sn-2 position of phsophatidylcholine to produce lysophosphatidylcholine and a free fatty acid.
A. pancreatic colipase
B. gastric lipase
C. pancreatic phospholipase A2
D. carboxylester lipase

Back 139

C. pancreatic phospholipase A2

Front 140

Which of the following statements is true concerning dietary fiber.
A. Chitosan is the most deacetylated form of chitin.
B. Dietary fiber slows gastric emptying.
C. Dietary fiber Impairs intestinal absorption of cholesterol and bile acids
D. All of the above
E. A and B

Back 140

D. All of the above

Front 141

Cleavage of starch to its final oligosaccharide products is completed in the _____.
A. ileum
B. stomach
C. mouth
D. duodenum
E. colon

Back 141

D. duodenum

Front 142

Galactose is transported from the cytosol of the enterocyte across the basolateral membrane via the GLUT2 transporter.
A. True
B. False

Back 142

A. True

Front 143

Which of the following helps to address the problem of lipid insolubility?
A. Emulsification
B. Micellar solubilization
C. Packaging into liposacchrides
D. A and B
E. All of the above

Back 143

D. A and B

Front 144

Gastric lipase hydrolyzes triaclyglycerol in which position?
A. Sn-1
B. Sn-2
C. Sn-3

Back 144

C. Sn-3

Front 145

The chemical digestion of lipid begins in the stomach.
A. True
B. False

Back 145

A. True

Front 146

Salivary amylase continues to cleave α(1,4) glycosidic bonds in the food bolus while in the stomach.
A. True
B. False

Back 146

A. True

Front 147

The Codex Alimentarius Commission defined functional fiber as isolated, nondigestible carbohydrates that have beneficial physiological effects in humans.
A. True
B. False

Back 147

B. False

Front 148

46. This fiber is the most abundant structural carbohydrate in nature.
A. hemicellulose
B. chitan
C. cellulose
D. inulin
E. lignin

Back 148

C. cellulose

Front 149

The abbreviation for N-acetylgalactosamine is _____.
A. GlcNAc
B. GlcA
C. GalNAc
D. Man
E. IdoA

Back 149

C. GalNAc

Front 150

Epimers are defined as _____.
A. molecules that are mirror images of one another.
B. molecules that undergo denaturation.
C. molecules that contain a carbonyl group at the C2 carbon.
D. molecules in which their configuration varies at only one carbon.
E. molecules that contain β(1,2) glycosidic linkages.

Back 150

D. molecules in which their configuration varies at only one carbon.

Front 151

Sucrose is composed of ___?
A. glucose and glucose.
B. glucose and fructose
C. glucose and galactose.
D. lactose and inositol
E. galactose and fructose

Back 151

B. glucose and fructose

Front 152

The systematic name for ribulose is _____.
A. D-Erythro-pentulose
B. D-Arabino-hexulose
C. D-Threo-pentulose
D. D-altro-heptulose
E. D-Arabinose

Back 152

A. D-Erythro-pentulose

Front 153

The furanose ring structure occurs in ketoses occurs with a reaction of carbon 1 (C1) with carbon 5 (C5).
A. True
B. False

Back 153

B. False

Front 154

A reducing sugar is one in which the terminal sugar contains an unsubstituted anomeric hydroxyl (OH) group.
A. True
B. False

Back 154

A. True

Front 155

Glycogen has 10 to 14 glucose units between branch points.
A. True
B. False

Back 155

A. True

Front 156

Another name for sialic acid is _____.
A. N-acetyl-glucosamine
B. N-acetyl-galactosamine
C. L-fucose
D. cerebroside
E. N-acetyl-neuraminic acid

Back 156

E. N-acetyl-neuraminic acid

Front 157

Maltose consists of ___.
A. two fructose molecules
B. lactose and deoxyribose
C. glucose and sucrose
D. two glucose molecules
E. glucose and galactose

Back 157

D. two glucose molecules

Front 158

Which of the following statements is true concerning starch?
A. Starch consists of glucose polymers found in plants.
B. There are 10 to 14 glucose units between branch points
C. Approximately 15% of dietary starches are resistant to digestion.
D. All of the above
E. A and C

Back 158

E. A and C

Front 159

The general structure of a glycosaminoglycan involves an N-acetylated sugar and an uronic acid. Which glycosaminoglycan contains D-galactose in place of an uronic acid residue?
A. Keratan sulfate
B. Hyaluronic acid
C. Heparin
D. Dermatan sulfate
E. Chondroitin sulfate

Back 159

A. Keratan sulfate

Front 160

A glycoside is any molecule in which a sugar group is bonded through its anomeric carbon to another group via a glycosidic bond.
A. True
B. False

Back 160

A. True

Front 161

Which of the following statements is true concerning glycogen?
A. Covalently linked β -particles can form 300 nm α -particles in cells.
B. Glycogen contains a core protein, glycogenin.
C. Glycogen has relatively low viscosity in water because it contains more branching that starch.
D. All of the above
E. B and C

Back 161

D. All of the above

Front 162

17. What is the major difference between globosides and gangliosides?
A. Only globosides contain ceramide.
B. The lactosyl portion (glucose/galactose) of the gangliosides is bound to ceramide by an N-glycosidic bond.
C. Sialic acid is attached by an O-glycosidic bond to lactosylceramide.
D. A and B
E. B and C

Back 162

C. Sialic acid is attached by an O-glycosidic bond to lactosylceramide.

Front 163

Which of the following amino acids is a hydroxyamino acid?
A. Histidine
B. Selenocysteine
C. Serine
D. Isoleucine
E. Methionine

Back 163

C. Serine

Front 164

Choose the correct statement concerning protein secondary structure.
A. The amino acid sequence will determine how the polypeptide folds to produce its secondary structure.
B. The secondary structure involves the folding of the polypeptide into two or more structurally different domains.
C. Oligomerization is a key component of the secondary structure of a protein.
D. All of the above
E. B and C

Back 164

A. The amino acid sequence will determine how the polypeptide folds to produce its secondary structure.

Front 165

Posttranslational modifications of a protein are important because____.
A. They determine the amino acid sequence of a protein during its synthesis (mRNA protein; translation).
B. They can add groups on to the amino acid side chains that are necessary for the protein function.
C. They can activate enzymes that are zymogens by removing small peptide fragments.
D. A and B
E. B and C

Back 165

E. B and C

Front 166

Which of the following amino acids are nonproteinogenic?
A. Citrulline
B. Homocysteine
C. Selenocysteine
D. A and B
E. B and C

Back 166

D. A and B

Front 167

Hemoglobin is an excellent example of protein quaternary structure because____.
A. the amino acid sequence is known.
B. it has heme prosthetic groups.
C. it carries oxygen.
D. it is a heterotetramer – it has four separate subunits that are joined together.
E. B and C

Back 167

D. it is a heterotetramer – it has four separate subunits that are joined together.

Front 168

What is the one-letter symbol for the cell surface binding domain peptide sequence: Arginine-Glycine-Aspartate-Serine
A. BGQS
B. RGDS
C. AGSI

Back 168

B. RGDS

Front 169

Which of the following amino acids is a branched-chain amino acid metabolized in muscle?
A. Cysteine
B. Valine
C. Glycine
D. Tyrosine
E. Alanine

Back 169

B. Valine

Front 170

The primary structure of a protein is its amino acid sequence.
A. True
B. False

Back 170

A. True

Front 171

The carbon that is designated by the arrow is the chiral carbon for this amino acid.
A. True
B. False

Back 171

B. False

Front 172

Which of the following statements is true concerning amino acids and/or peptides?
A. Amino acids contain no net charge.
B. Amino acids contain both positive and negative ions.
C. Amino acids within peptides are zwitterions.
D. All of the above
E. A and B

Back 172

D. All of the above

Front 173

The portion of a polypeptide enriched in amino acids that have free rotation around the polypeptide chain will result in a β-sheet when next to a similar polypeptide section.
A. True
B. False

Back 173

B. False

Front 174

Which amino acid is the first amino acid as polypeptide synthesis occurs in humans.
A. Cysteine
B. Methionine
C. Serine
D. Asparagine
E. Threonine

Back 174

B. Methionine

Front 175

A prochiral carbon is defined as one in which three of four of its bound groups are different.
A. True
B. False

Back 175

A. True

Front 176

The most abundant acylglycerols are the ___.
A. triacylglycerols
B. diacylglycerols
C. monoacylglycerols

Back 176

A. triacylglycerols

Front 177

Choose the correct statement concerning inositol as the head group in glycerolphospolipids.
A. The inner leaflet of the lipid bilayer will contain phosphatidyl inositol-containing phospholipids.
B. Phosphotidyl inositol-containing phospholipids can be phosphorylated and participate in the docking of proteins, second messenger and signal transduction functions.
C. Phosphatidyl inositol is a component of glycosylphosphatidylinositol (GPI) membrane anchors that anchor certain cell-surface proteins.
D. All of the above
E. A and B

Back 177

D. All of the above

Front 178

Which of the carbons in the figure will be esterified to fatty acids in the glycerophospholipids that compose the lipid bilayer of biological membranes?
A. carbons sn-1 and sn-2
B. carbon sn-2
C. carbon sn-3
D. carbons sn-1 and sn-3
E. carbon sn-1

Back 178

A. carbons sn-1 and sn-2

Front 179

The class of eicosanoids produced by cyclooxygenases is____.
A. 5S, 15S-DiHETE (dihydroxy eicosatetraenoic acid)
B. prostaglandins and thromboxanes
C. leukotrienes and lipoxins

Back 179

B. prostaglandins and thromboxanes

Front 180

The International Union of Pure and Applied Chemistry use an abbreviated notation for unsaturated fatty acids. Reading from left to right, what does each item in the following notation mean… 20:4n-6?
A. 20 is the number of carbons; 4 is the number of double bonds; n-6 means the first double bond from the carboxyl end is at the number 6 carbon.
B. 20 is the number of carbons; 4n-6 means that each carbon contains a double bond.
C. 20 is the number of carbons; 4 is the number of double bonds; n-6 is the total number of carbons minus 6, which is where the double bond closest to the methyl end is found.

Back 180

C. 20 is the number of carbons; 4 is the number of double bonds; n-6 is the total number of carbons minus 6, which is where the double bond closest to the methyl end is found.

Front 181

cis-9,12-octadecadienoic acid is the systematic name for ___.
A. 16:0 -palmitic acid
B. 20:5n-3 -EPA
C. 20:4n-6 -arachadonic acid
D. 18:2n-6 -linoleic acid
E. 22:6n-3 -DHA

Back 181

D. 18:2n-6 -linoleic acid

Front 182

Which of the carbons in the figure is a prochiral carbon?
A. carbons sn-1 and sn-2
B. carbon sn-2
C. carbon sn-3
D. carbons sn-1 and sn-3
E. carbon sn-1

Back 182

B. carbon sn-2

Front 183

An example of a diphosphatidylglycerol is ___.
A. lysophospholipids
B. cardiolipin
C. plasmalogens
D. platelet activating factors
E. sphingolipids

Back 183

B. cardiolipin

Front 184

Which of the following statements is true concerning sphingolipids?
A. Sphingolipids contain only one fatty acid chain.
B. Glycerol is replaced as the lipid backbone by sphingosine.
C. Glycosphingolipids that contain sulfate groups and/or sialic acid residues are acidic.
D. All of the above
E. B and C

Back 184

D. All of the above

Front 185

Which of the following statements is true concerning isoprenoids?
A. Isoprenoids are large compounds containing up to 18 carbon chains.
B. An important isoprenoid-containing compound is ubiquinone (coenzyme Q) which is involved in electron transport.
C. The basic unit of an isoprenoid is a 5-carbon monomeric unit.
D. All of the above
E. B and C

Back 185

E. B and C

Front 186

The basic structure of steroids is composed of four rings – three cyclohexane rings and one cyclopentane ring.
A. True
B. False

Back 186

A. True

Front 187

Which of the carbons in the figure will be esterified to a phosphate group in the glycerophospholipids that compose the lipid bilayer of biological membranes?
A. carbons sn-1 and sn-2
B. carbon sn-2
C. carbon sn-3
D. carbons sn-1 and sn-3
E. carbon sn-1

Back 187

C. carbon sn-3

Front 188

Most of cholesterol in cells is present in membranes.
A. True
B. False

Back 188

A. True

Front 189

Choose the correct statement concerning bile acids from the choices below.
A. Bile acids are synthesized in the adrenal gland.
B. Cholesterol is converted to a bile acid by removal of carbons 25 through 27 and replacing them with a carboxyl group (-COOH) at carbon 24.
C. The synthesis of bile acids involved the disruption and removal of one of the cyclohexane rings.
D. Bile acids are synthesized in the liver.
E. B and D

Back 189

E. B and D

Front 190

The class of eicosanoids produced by lipoxygenases is____.
A. 5S, 15S-DiHETE (dihydroxy eicosatetraenoic acid)
B. prostaglandins and thromboxanes
C. leukotrienes and lipoxins

Back 190

C. leukotrienes and lipoxins