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MCM BCHE > Practice Questions > Flashcards

Practice Questions Flashcards

1
Q

What is the major contributor to lipid bilayer self assembly?

A. Van der waals forces
B. Electrostatic interactions
C. Hydrophobic interactions
D. Hydrogen bonds

A

C. Hydrophobic interactions

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2
Q

What of the following modifications would result in the formation of a thioester bond involving a specific amino acid?

A. Palmitoylation of cysteine residues
B. Palmitoylation of aspartate residues
C. Farnesylation of cysteine residues
D. Farnesylation of aspartate residues

A

A. Palmitoylation of cysteine residues

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3
Q

What is the site of most of the TCA cycle and fatty acid oxidation in the mitochondria?

A. Intermembrane space
B. Inner membrane
C. Outer membrane
D. Matrix

A

D. Matrix

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4
Q

Which of the following fuels has the lowest caloric content?

A. Carbs
B. Fats
C. Alcohols
D. Lipids

A

A. Carbs

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5
Q

Essential amino acids are very crucial for maintaining health; if not taking them sufficiently in the diet, a person would have a _____________

A. Positive nitrogen balance
B. Positive phosphorus balance
C. Negative nitrogen balance
D. Negative phosphorus balance

A

C. Negative nitrogen balance

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6
Q

Glucose and fructose are monosaccharides that make up which disaccharide?

A. Lactose
B. Maltose
C. Ribose
D. Sucrose

A

D. Sucrose

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7
Q

Which of the following is one of the most biologically active minerals required in the diet?

A. Iodine
B. Chloride
C. Manganese
D. Molybdenum

A

B. Chloride

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8
Q

Which of the following is a purine base?

A. Thymine
B. Inosine
C. Adenosine
D. Hypoxanthine

A

D. Hypoxanthine

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9
Q

Place the required enzymes in order for the digestion of DNA when starting with a long DNA chain

A. Nucleotidase, nucleosidase, phosphodiesterase, deoxyribonuclease
B. Deoxyribonuclease, phosphodiesterase, nucleotidase, nucleosidase
C. Phosphodiesterase, nucleotidase, nucleosidase, deoxyribonuclease
D. Deoxyribonuclease, nucleotidase, nucleosidase, phosphodiesterase

A

B. Deoxyribonuclease, phosphodiesterase, nucleotidase, nucleosidase

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10
Q

What are the primary regulatory mechanisms involved in the committed step of de novo purine nucleotide synthesis?

A. PRPP stimulates, purine nucleotides inhibit
B. Purine nucleotides stimulate, PRPP inhibits
C. Phosphate stimulates, purine nucleotides inhibit
D. Purine nucleotides stimulate, phosphate inhibits

A

A. PRPP stimulates, purine nucleotides inhibit

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11
Q

What occurs during the committed step of de novo purine nucleotide synthesis?

A. Addition of amino group to PRPP
B. Cleavage of phosphate group off of PRPP
C. Addition of carbonyl group to PRPP
D. Opening of the PRPP ring

A

A. Addition of amino group to PRPP

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12
Q

Regarding nucleotide metabolism, what is the likely state of the synthesized nucleotide if the body is in a state of fasting?

A. Monophosphate form
B. Triphosphate form
C. Diphosphate form
D. Tetraphosphate form

A

B. Triphosphate form

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13
Q

What would be a likely consequence of a dysfunction of UMP synthase?

A. Buildup of UMP
B. Buildup of CDP
C. Buildup of orotate
D. Buildup of carbamoyl aspartate

A

C. Buildup of orotate

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14
Q

Adenine phosphoribosyl-transferase is an important enzyme utilized in which of the following pathways?

A. Pyrimidine nucleotide salvage
B. De novo purine syntheis
C. De novo pyrimidine synthesis
D. Purine nucleotide salvage

A

D. Purine nucleotide salvage

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15
Q

Which of the following glucose transporters is insulin-dependent?

A. GLUT1
B. GLUT2
C. GLUT3
D. GLUT4

A

D. GLUT4

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16
Q

In what state is glucose considered “trapped” in the cell, at which time the only organ that can convert it to free glucose is the liver?

A. Glucose 6-phosphate
B. Glucose 1-phosphate
C. Glucose 2,6 bisphosphate
D. Glucose 3-phosphate

A

A. Glucose 6-phosphate

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17
Q

What are the primary regulators of phosphofructokinase?

A. Inhibition by F-2,6-BP activation by citrate
B. Inhibition by hexokinase, activated by citrate
C. Inhibition by pyruvate kinase, activation by F-2,6-BP
D. Inhibition by citrate, activation by F-2,6-BP

A

D. Inhibition by citrate, activation by F-2,6-BP

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18
Q

What are two necessary enzymes needed to get from pyruvate to glyceraldehyde 3-phosphate in gluconeogenesis?

A. Pyruvate carboxylase and phosphoenolpyruvate kinase via bypass reaction
B. Pyruvate kinase and phosphoenolpyruvate kinase via bypass reaction
C. Pyruvate carboxylase and phosphoenolpyruvate kinase via direct reaction
D. Pyruvate kinase and enolase via bypass reaction

A

A. Pyruvate carboxylase and phosphoenolpyruvate kinase via bypass reaction

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19
Q

Which of the following is not an enzyme involved in an irreversible reaction of glycolysis in the liver?

A. Glucokinase
B. Pyruvate kinase
C. G3P dehydrogenase
D. Phosphofructokinase

A

C. G3P dehydrogenase

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20
Q

Which of the following is/are positive regulator(s) of glycolysis?

A. Citrate
B. AMP
C. F-2,6-BP
D. B and C
E. None of the above
A

D. B and C

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21
Q

What effect would high AMP levels have on glycogen phosphorylase in the liver?

A. The phosphorylase would be activated due to low energy charge
B. The phosphorylase would be inactivated due to low energy charge
C. The phosphorylase would be inactivated due to high energy charge
D. The phosphorylase would not respond to changes in AMP levels

A

D. The phosphorylase would not respond to changes in AMP levels

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22
Q

What effect does branching of glycogen chains have on the molecules?

A. Increases solubility and increases rate of synthesis/degradation
B. Decreases solubility but increases rate of synthesis/degradation
C. Increases solubility but decreases rate of synthesis/degradation
D. Decreases solubility and decreases rate of synthesis/degradation

A

A. Increases solubility and increases rate of synthesis/degradation

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23
Q

Phosphorylation of glycogen synthase kinase would have what effect on glycogenesis?

A. Activation of glycogen synthase, thus promoting the syntehsis of glycogen
B. Inactivation of glycogen synthase, thus inhibiting the synthesis of glycogen
C. Activation of glycogen phosphorylase, thus promoting the synthesis of glycogen
D. Inactivation of glycogen phosphorylase, thus inhibiting the synthesis of glycogen

A

B. Inactivation of glycogen synthase, thus inhibiting the synthesis of glycogen

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24
Q

Amylopectin differs from amylose in what way?

A. It is considered a starch
B. It is linear
C. It is branched
D. It has (alpha) 1,4-glycosidic linkages

A

C. It is branched

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25
Q

Why is high fructose corn syrup more fattening than typical sugars?

A. It can enter glycolysis directly into GAP/DHAP step
B. It can be directly broken down into TAG
C. It is stored directly upon consumption
D. It is the last type of fat to be broken down for energy

A

A. It can enter glycolysis directly into GAP/DHAP step

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26
Q

What is the nucleotide abbreviation for hypoxanthine?

A. XMP
B. HMP
C. IMP
D. OMP

A

C. IMP

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27
Q

Which of the following products of nucleotide catabolism can be transformed to ketone bodies, which can then be transported to the brain?

A. Beta-aminoisobutyrate
B. Methylmalonyl CoA
C. Malonyl CoA
D. Succinyl CoA

A

C. Malonyl CoA

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28
Q

Which of the following is formed from the committed step in purine synthesis?

A. PRPP
B. Phosphoribosyl amine
C. Carbamoyl aspartate
D. Methotrexate

A

B. Phosphoribosyl amine

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29
Q

Which enzyme does methotrexate target?

A. Dihydrofolate reductase
B. Ribonucleotide reductase
C. PRPP synthase
D. Dihydroorotate dehydrogenase

A

A. Dihydrofolate reductase

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30
Q

Which of the following enzymes must be bypassed for gluconeogenesis to occur?

A. Enolase
B. Aldolase
C. G3P dehydrogenase
D. Pyruvate kinase

A

D. Pyruvate kinase

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31
Q

Which of the following steps of gluconeogenesis occurs in the mitochondria?

A. Conversion of G6P to glucose
B. Conversion of oxaloacetate to PEP
C. Conversion of G6P to Fructose 1,6-BP
D. Conversion of pyruvate to oxaloacetate

A

D. Conversion of pyruvate to oxaloacetate

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32
Q

What enzyme in glycolysis would be the next to act on the product of glycogenolysis coming from the liver?

A. Glucokinase
B. PFK
C. G3P dehydrogenase
D. Pyruvate kinase

A

A. Glucokinase

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33
Q

Which of the following occurs in the cytosol?

A. TCA
B. B-ox
C. Glycolysis
D. Oxphos

A

C. Glycolysis

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34
Q
  1. In glycolysis, most enzymatic reactions are reversible and can also be used for gluconeogenesis. However, there are 3 glycolysis reactions that are irreversible, and different enzymes are required to bypass them in gluconeogenesis. Which of the following enzymes catalyzes such an irreversible step?

A. Phosphoglucose isomerase
B. Phosphofructokinase-1
C. Aldolase A
D. Phosphoglycerate kinase

A

B. Phosphofructokinase-1

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35
Q

An athlete runs 800 m in a national training center. Afterward, a blood sample is taken and analyzed. Which compound would you expect to find elevated?

A. Glucose
B. Lacate
C. Beta-hydroxybutyrate
D. Free fatty acids

A

B. Lactate

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36
Q
  1. A newborn girl is transferred to the neonatal intensive care unit for severe nonspherocytic hemolytic anemia and jaundice. She was born by C-section at week 32 as the third child to a first-cousin couple; none of her older siblings has survived. She was given 2 exchange transfusions on her 1st day and phototherapy for 8 days. She was maintained with monthly red blood cell transfusions until a splenectomy was performed at age 3. From then on, transfusions were required only rarely, usually after infections. Her mental development was normal, physical development was delayed. She is now 13 years old. Investigating the metabolite concentrations in the erythrocytes of this patient (before the 1st transfusion) resulted in the following: high levels of glucose-6-phosphate, 1,3-bisphosphoglycerate, 3-phosphoglycerate, phosphoenolpyruvate, ADP, and AMP and low levels of ATP, pyruvate, and lactate. Which of the following glycolytic enzymes is most likely defective?

A. Pyruvate kinase
B. Enolase
C. Hexokinase
D. Phosphoglycerate kinase

A

A. Pyruvate kinase

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37
Q

Which readily available intermediate from glycolysis is used as a direct precursor for the synthesis of the glycerol moiety of TAGs?

A. Pyruvate
B. Glycerol-3 phosphate
C. 3-phosphoglycerate
D. Dihydroxyacetone phosphate

A

D. Dihydroxyacetone phosphate

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38
Q

Which of the following is not a direct product of the TCA cycle?

A. ATP
B. GTP
C. Carbon dioxide
D. Electron carriers

A

A. ATP

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39
Q

What enzyme is associated with the release of a high energy phosphoryl transfer compound from TCA?

A. Aconitase
B. Succinyl CoA synthetase
C. Succinate dehydrogenase
D. Fumarase

A

B. Succinyl CoA synthetase

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40
Q

Under anaerobic conditions, what is the fate of pyruvate?

A. Lactate
B. Ethanol
C. Acetyl CoA
D. A and B
E. None of the above
A

D. A and B

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41
Q

Which part of PDH is known for being the actual dehydrogenase component and what is its prosthetic group?

A. E1; lipoamide
B. E2; TPP
C. E1; TPP
D. E2; lipoamide

A

C. E1; TPP

42
Q

Which of the following is not a stoichiometric cofactor associated with the PDH complex?

A. CoA
B. NAD+
C. NADH
D. None of the above

A

C. NADH

43
Q

True or False:

High acetyl CoA directly inhibits E2 of PDH

A

True

44
Q

An accumulation of ADP and pyruvate activate what type of enzyme, leading to what result for PDH?

A. Phosphatases; removal of a phosphate group and PDH activation
B. Phosphatases; removal of a phosphate group and PDH inhibition
C. Kinases; addition of a phosphate group and PDH activation
D. Kinases; addition of a phosphate group and PDH inhibition

A

A. Phosphatases; removal of a phosphate group and PDH activation

45
Q

What enzyme is responsible for the condensation of oxaloacetate and acetyl group of acetyl CoA during the TCA cycle?

A. Isocitrate dehydrogenase
B. Malate synthase
C. Citrate synthase
D. Aconitase

A

C. Citrate synthase

46
Q

What is the first of 4 redox reactions in the TCA cycle and why is this step important?

A. Isocitrate dehydrogenase; because it is the rate limiting step
B. Alpha-ketoglutarate dehydrogenase; because it is the rate limiting step
C. Isocitrate dehydrogenase; because it is allosterically stimulated by ADP, enhancing enzyme affinity for substrate
D. Alpha-ketoglutarate dehydrogenase; because it is most similar to the PDH complex
E. A and C

A

E. A and C

47
Q

Which of the following directly inhibits E2 of the PDH complex?

A. High acetyl CoA
B. Increased NADH
C. Increased pyruvate
D. All of the above
E. A and B only
A

E. A and B only

48
Q

ADP acts as an activator at which points in the TCA cycle?

A. Citrate synthase and isocitrate dehydrogenase
B. Isocitrate dehydrogenase and succinyl CoA synthetase
C. Succinate dehydrogenase and malate dehydrogenase
D. Aconitase and isocitrate dehydrogenase

A

A. Citrate synthase and isocitrate dehydrogenase

49
Q

True or false:

Oxaloacetate plays a role in glycolysis and it will go there if we are not breaking it down in TCA

A

False - OAA plays a role in gluconeogenesis, not glycolysis

50
Q

Which of the following is incorrectly matched?

A. Ox Phos - Matrix
B. TCA cycle - Matrix
C. Fatty acid oxidation - Matrix
D. Al of the above are correct

A

A. Ox Phos - Matrix

Oxidative phosphorylation (ETC + ATP synthase) is located on the inner membrane

51
Q

True or false:

The electron flow through the ETC is exergonic

A

True

52
Q

What is the first point of entry in the ETC for electrons from NADH?

A. Complex I
B. Complex II
C. Complex III
D. Complex IV

A

A. Complex I

53
Q

FMN is a derivative of what vitamin?

A. A
B. B
C. K
D. D

A

B. B

54
Q

Which of the following catalyzes the conversion of hydrogen peroxide free radicals into oxygen and water?

A. Superoxide dismutase
B. Glutathione peroxidase
C. Catalase
D. Peroxidase

A

C. Catalase

55
Q

True or false:

An alkaline pH in the mitochondrial matrix is part of what constitutes the proton motive force that is used to drive ATP synthesis

A

True

56
Q

What is the role of the proton gradient powering ATP synthesis?

A. The proton gradient is used to synthesize the ATP itself
B. The proton gradient works through a second messenger signaling cascade
C. The proton gradient works to release ATP from the ATP synthase complex
D. The proton gradient provides a positive feedback mechanism for ATP synthesis

A

C. The proton gradient works to release ATP from the ATP synthase complex

57
Q

Which inhibitor of oxidative phosphorylation does so by dissipating the proton gradient?

A. 2,4-dinitrophenol
B. Oligomycin
C. Atractyloside
D. Bongkrekik acid

A

A. 2,4-dinitrophenol

58
Q

What is the rate limiting enzyme in the pentose phosphate pathway, and in what phase does it occur?

A. Glucose-6-phosphate dehydrogenase; oxidative phase
B. Glucose-6-phosphate dehydrogenase; non-oxidative phase
C. Glucokinase: oxidative phase
D. Hexokinase; non-oxidative phase

A

A. Glucose-6-phosphate dehydrogenase; oxidative phase

59
Q

Glutathione is essential in its _________ form to maintain healthy RBC membranes, because its _________ form creates unstable disulfide bonds and promotes reactive oxygen species formation

A. Oxidized; reduced
B. Reduced; oxidized
C. Neutral; reduced
D. Oxidized; neutral

A

B. Reduced; oxidized

60
Q

Chylomicrons are hydrophobic packages containing proteins, phospholipids, cholesterol, and fat-soluble vitamins. What is the major apoprotein associated with chylomicrons?

A. Apo CII
B. Apo E
C. Apo B100
D. Apo B48

A

D. Apo B48

61
Q

The mobilization of fatty acids from adipocytes involves a second messenger signaling cascade initiated by either glucagon or epinephrine, eventually activating protein kinase A. Which enzyme, activated by PKA, is responsible for cleaving a diacylglyceride to a monoacylglyceride?

A. Adipose triglyceride lipase
B. Perilipase
C. Hormone sensitive lipase
D. DAG lipase

A

C. Hormone sensitive lipase

62
Q

Where and how does the metabolism of glycerol occur?

A. In hepatocytes via glycerol kinase
B. In mitochondria via glycerol phosphatase
C. In hepatocytes via glucose-6-phosphatase
D. In mitochondria via glucose-6-phosphatase

A

A. In hepatocytes via glycerol kinase

63
Q

The first reaction in fatty acid oxidation requires that FA be trapped in the cell and made metabolically active by what enzyme?

A. Acyl-CoA synthetase
B. Acyl-CoA dehydrogenase
C. Enoyl CoA hydratase
D. Hydroxyacyl CoA Dehydrogenase

A

A. Acyl-CoA synthetase

64
Q

Which step in fatty acid beta-oxidation is not associated with the release of any major energy carriers?

A. The first oxidation via acyl CoA dehydrogenase
B. The hydration step via enoyl CoA hydratase
C. The second oxidation via hydroxyacyl CoA dehydrogenase
D. The thiolysis step via ketothiolase

A

B. The hydration step via enoyl CoA hydratase

65
Q

A deficiency in vitamin B12 (cobalamin) would result in the ability to continue breaking down fatty acids but with a buildup of what?

A. Succinyl CoA
B. Propionyl CoA
C. Acetyl CoA
D. Pyruvate

A

B. Propionyl CoA

66
Q

Which of the following is not a ketone body formed due to a diet low in carbohydrates?

A. Acetoacetate
B. Acetone
C. D-3-hydroxybutyrate
D. Acetophenone

A

D. Acetophenone

67
Q

Where does fatty acid synthesis primarily occur?

A. Adipose tissue
B. Liver
C. Renal cells
D. Neurons

A

B. Liver

68
Q

Fatty acid synthesis requires that pyruvate be converted to citrate in the mitochondria before being transported out and becoming OAA again by way of what enzyme?

A. Citrate lyase
B. Citrate ligase
C. OAA synthetase
D. OAA synthase

A

A. Citrate lyase

69
Q

What is the rate limiting enzyme of fatty acid biosynthesis and what cofactor does it require?

A. Acetyl CoA synthetase; vitamin B
B. Acetyl CoA carboxylase; vitamin B
C. Acetyl CoA synthetase; biotin
D. Acetyl CoA carboxylase; biotin

A

D. Acetyl CoA carboxylase; biotin

70
Q

Acetyl CoA Carboxylase is positively regulated by which of the following?

A. Citrate
B. Insulin
C. Pyruvate
D. All of the above
E. A and B only
A

E. A and B only

71
Q

Place the reactions of fatty acid synthesis in the order in which they occur:

A. Condensation, oxidation, dehydration, oxidation
B. Oxidation, hydration, oxidation, thiolysis
C. Condensation, reduction, dehydration, reduction
D. Reduction, condensation, reduction, dehydration

A

C. Condensation, reduction, dehydration, reduction

72
Q

Desaturation of fatty acids occurs in the ________ of the cell in a process in which stearoyl CoA and oxygen are utilized to produce water and _________.

A. ER; oleoyl CoA
B. ER; succinyl CoA
C. Mitochondria; succinyl CoA
D. Mitochondria; malonyl CoA

A

A. ER; oleoyl CoA

73
Q

In the synthesis of TAG, part of the pathway begins with glycerol in the liver and the other part starts with glucose in fat cells/adipose tissue. At which point do these two potential pathways converge?

A. Phosphatidic acid
B. Diacylglycerol
C. Glycerol 3-P
D. Glycerol 6-P

A

C. Glycerol 3-P

74
Q

Cholesterol is not a precursor for which of the following:

A. Bile salts
B. Progesterone
C. Cortisol
D. Cholesterol is a precursor to all of the above

A

D. Cholesterol is a precursor to all of the above

75
Q

Which of the following has the highest concentration of cholesterol?

A. VLDL
B. IDL
C. LDL
D. HDL

A

C. LDL

76
Q

Which of the following has the highest protein and phospholipid content?

A. VLDL
B. IDL
C. LDL
D. HDL

A

D. HDL

77
Q

There are 3 general components to amino acid metabolism: aminotransferse, glutamate dehydrogenase, and the urea cycle. Which 2 amino acids are able to bypass the glutamate dehydrogenase reaction because they are directly deaminated?

A. Aspartate and Lysine
B. Tryptophan and Threonine
C. Serine and Threonine
D. Serine and Aspartate

A

C. Serine and Threonine

78
Q

Which of the following is true regarding amino acid metabolism?

A. It is irreversible and is drive forward by a negative delta G
B. It is irreversible and does not occur spontaneously
C. It is reversible and is driven forward by an excess of protein in the body
D. It is reversible and is driven forward by removal of ammonium

A

D. It is reversible and is driven forward by removal of ammonium

79
Q

Aminotransferases require what vitamin derived coenzyme?

A. Pyridoxyl-5’-phosphate, derivative of vitamin B6
B. Pantothene-5’-phosphate, derivative of vitamin D
C. Pyridoxyl-5’-phosphate, derivative of vitamin C
D. Pyridoxyl-5’-phosphate, derivative of vitamin B12

A

A. Pyridoxyl-5’-phosphate, derivative of vitamin B6

80
Q

Which amino acid-based aminotransferases are clinically relevant markers for liver damage?

A. Alanine and asparagine
B. Aspartate and alanine
C. Asparagine and aspartate
D. Alanine and serine

A

B. Aspartate and alanine

81
Q

Cleavage of which of the following links the urea cycle to the TCA cycle?

A. Citrulline
B. Ornithine
C. Carbamoyl phosphate
D. Argininosuccinate

A

D. Argininosuccinate

Argininosuccinate is cleaved into arginine and fumarate. Arginine continues through the urea cycle while fumarate can be shunted to TCA

82
Q

What is the ratio of [glucogenic] to [ketogenic or glucogenic] to [ketogenic] amino acids?

A. 2:5:13
B. 13:5:2
C. 2:6:13
D. 6:13:2

A

B. 13:5:2

83
Q

During the urea cycle, ammonium ions react with bicarbonate ions, coupled with the hydrolysis of 2 ATP, to form ________ via rate-limiting enzyme: __________

A. Ornithine; ornithine synthetase
B. Arginine phosphate; ornithine phosphatase II
C. Carbamoyl phosphate; carbamoyl phosphate synthetase
D. Citrulline phosphate; citrulline phosphate synthetase

A

C. Carbamoyl phosphate; carbamoyl phosphate synthetase

84
Q

What are the substrates and products of the alanine aminotransferase catalyzed reaction?

A. Substrates: Pyruvate and Glutamate; Products: Alanine and Alpha-ketoglutarate
B. Substrates: Pyruvate and Oxaloacetate; Products: Alanine and Glutamate
C. Substates: Oxaloacetate and Glutamate; Products: Aspartate and alpha-ketoglutarate
D. Substrates: Alanine and Aspartate; Products: Oxaloacetate and Glutamate

A

A. Substrates: Pyruvate and Glutamate; Products: Alanine and Alpha-ketoglutarate

[Answer choice C would be the aspartate aminotransferase reaction]

85
Q

Which of the following is not strictly a glucogenic amino acid?

A. Val
B. Leu
C. Glu
D. Pro

A

B. Leu

[Leu and Lys are strictly ketogenic]

86
Q

Which of the following represents and amino acid metabolic entry point for 5-carbon amino acids by means of glutamate formation?

A. Alpha ketoglutarate
B. Succinyl CoA
C. Oxaloacetate
D. Pyruvate

A

A. Alpha ketoglutarate

87
Q

Which of the following represents an amino acid metabolic entry point for Asp and Asn?

A. Alpha-ketoglutarate
B. Succinyl CoA
C. Oxaloacetate
D. Pyruvate

A

C. Oxaloacetate

88
Q

Which of the following represents an amino acid metabolic entry point for amino acids such as Methionine, Valine, or Isoleucine?

A. Alpha-ketoglutarate
B. Succinyl CoA
C. Oxaloacetate
D. Pyruvate

A

B. Succinyl CoA

[nonpolar amino acids may enter at succinyl CoA]

89
Q

What important enzyme is utilized in the conversion of phenylalanine to fumarate and what inborn error of metabolism results when this enzyme is deficient?

A. Phenylalanine phosphatase; MSUD
B. Phenylalanine aminotransferase; MSUD
C. Phenylalanine hydroxylase; PKU
D. Fumarate aminotransferase; PKU

A

C. Phenylalanine hydroxylase; PKU

90
Q

Which of the following is not a key junction point of all the major metabolic pathways?

A. Glucose 6-phosphate
B. Fructose 6-phosphate
C. Acetyl CoA
D. Pyruvate

A

B. Fructose 6-phosphate

91
Q

Which of the following is not a potential fate of pyruvate?

A. Alanine
B. Oxaloacetate
C. Lactate
D. Ribose 5-P

A

D. Ribose 5-P

92
Q

The tissues and organs of the body are specialized when it comes to metabolism. What organ/tissue processes fats, carbs, and proteins while distributing lipids, ketone bodies, and glucose to other tissues?

A. Pancreas
B. Small intestine
C. Skeletal muscle
D. Liver

A

D. Liver

93
Q

Adipose tissue is responsible for storing TAGs and releasing fatty acids to each of the following except:

A. Pancreas
B. Skeletal muscle
C. Heart
D. Liver

A

A. Pancreas

94
Q

Which of the following is the correct order of energy system utilization, from immediate to long-term energy production?

A. Anaerobic glycolysis, phosphagen system, oxidative system
B. Phosphagen system, anaerobic glycolysis, oxidative system
C. Oxidative system, phosphagen system, anaerobic glycolysis
D. Oxidative system, anaerobic glycolysis, phosphagen system

A

B. Phosphagen system, anaerobic glycolysis, oxidative system

95
Q

Insulin binding to a RTK triggers autophosphorylation at which of the following residues?

A. Tyr
B. Phe
C. Ala
D. Asp

A

A. Tyr

96
Q

True or false:

When glucagon levels increase, they trigger fatty acid oxidation in skeletal muscle

A

False

Skeletal muscle does not have receptors for glucagon, only epinephrine

97
Q

In an extended fasting state, what hormone acts on the skeletal muscle to trigger protein degradation into amino acids?

A. Glucagon
B. Insulin
C. Epinephrine
D. Cortisol

A

D. Cortisol

98
Q

When you wake up in the morning in a fasted state, what is the likely activity of your AMPK?

A. AMPK is inactivated by reverse phosphorylation
B. AMPK is allosterically inactivated
C. AMPK is allosterically activated
D. AMPK is activated by reverse phosphorylation

A

C. AMPK is allosterically activated

99
Q

In what form is nitrogen removed from muscle?

A. Gln and Ser
B. Ala and Asp
C. Asp and Glu
D. Glu and Ala

A

D. Glu and Ala

100
Q

True or false:

Increased levels of cAMP decrease glycogen phosphorylase activity

A

False

MCM BCHE (13 decks)

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