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biochem 2 > Fatty Acid and Triacylglycerol Metabolism > Flashcards

Fatty Acid and Triacylglycerol Metabolism Flashcards

1
Q

What is the primary storage site for fatty acids in the body?
a) Liver
b) Muscle tissue
c) Adipose tissue
d) Bone marrow

A

c) Adipose tissue

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2
Q

What are the major physiological roles of fatty acids?
a) Fatty acids are primarily used as enzymes in metabolic pathways.
b) Fatty acids are structural components of carbohydrates.
c) Fatty acids serve as building blocks of proteins.
d) Fatty acids serve as fuel molecules, building blocks of phospholipids and glycolipids, targets for protein modification, and hormone and intracellular messenger precursors.

A

d) Fatty acids serve as fuel molecules, building blocks of phospholipids and glycolipids, targets for protein modification, and hormone and intracellular messenger precursors.

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3
Q

Which role do fatty acids play in the modification of proteins?
a) They serve as cofactors for enzyme reactions.
b) They serve as structural elements in protein folding.
c) They are attached covalently to proteins to target them to membrane locations.
d) They act as signaling molecules for protein synthesis.

A

c) They are attached covalently to proteins to target them to membrane locations.

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4
Q

How do fatty acid derivatives function in hormone and intracellular signaling?
a) They bind to DNA to regulate gene expression.
b) They directly activate enzymes involved in cellular metabolism.
c) They interact with cell surface receptors to initiate signaling cascades.
d) They transport ions across cell membranes.

A

c) They interact with cell surface receptors to initiate signaling cascades.

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5
Q

Where is white adipose tissue primarily located in the body?
a) Only in the liver
b) Only in muscles
c) Under the skin and surrounding internal organs
d) Only in the brain

A

c) Under the skin and surrounding internal organs

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6
Q

What is the major function of adipocytes?
a) Synthesis of cholesterol
b) Synthesis of glucose
c) Accumulation and storage of triacylglycerols
d) Synthesis of proteins

A

c) Accumulation and storage of triacylglycerols

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7
Q

What is the main role of adipose tissue in metabolism?
a) Breakdown of carbohydrates
b) Synthesis of nucleic acids
c) Storage and mobilization of triacylglycerols into fuel
d) Transport of oxygen

A

c) Storage and mobilization of triacylglycerols into fuel

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8
Q

What is an intracellular lipid droplet specialized for?
a) Synthesis of proteins
b) Synthesis of carbohydrates
c) Synthesis of phospholipids
d) Storage of triacylglycerols

A

d) Storage of triacylglycerols

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9
Q

How are ingested triacylglycerides degraded during dietary fat digestion?
a) By proteases
b) By lipases
c) By carbohydrases
d) By nucleases

A

b) By lipases

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10
Q

What is the role of bile salts during dietary fat digestion?
a) They act as enzymes to break down fats.
b) They emulsify triacylglycerides to make them accessible to lipases.
c) They transport fatty acids across the intestinal membrane.
d) They convert triacylglycerides into chylomicrons.

A

b) They emulsify triacylglycerides to make them accessible to lipases.

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11
Q

In what orientation is the glycerol head group of triacylglycerides positioned during digestion?
a) Toward the lipid bilayer
b) Toward the lumen of the intestines
c) Toward the bloodstream
d) Toward the aqueous environment where lipase resides

A

d) Toward the aqueous environment where lipase resides

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12
Q

What happens to triacylglycerides when they cross the intestines?
a) They are degraded into fatty acids and glycerol.
b) They are reformed.
c) They are converted into chylomicrons.
d) They are transported to the liver.

A

b) They are reformed.

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13
Q

How are triacylglycerides transported to adipose tissues after digestion?
a) Through the bloodstream
b) Through the lymphatic system within chylomicrons
c) Through the nervous system
d) Through the digestive system within bile salts

A

b) Through the lymphatic system within chylomicrons

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14
Q

What is the first stage required for the use of fatty acids as fuel?
a) Mobilization of lipids through phospholipid degradation
b) Activation of fatty acids in the mitochondria
c) Mobilization of lipids through triacylglycerol degradation
d) Transport of lipids to the liver

A

c) Mobilization of lipids through triacylglycerol degradation

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15
Q

What is involved in the second stage of processing fatty acids as fuel?
a) Degradation of fatty acids to acetyl CoA
b) Mobilization of lipids through triacylglycerol degradation
c) Activation of the fatty acids and transport into the mitochondria
d) Conversion of fatty acids into glucose

A

c) Activation of the fatty acids and transport into the mitochondria

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16
Q

What is the final stage in the processing of fatty acids for fuel utilization?
a) Mobilization of lipids through triacylglycerol degradation
b) Activation of fatty acids in the mitochondria
c) Degradation of fatty acids to acetyl CoA for processing in the citric acid cycle
d) Transport of lipids into the adipose tissue

A

c) Degradation of fatty acids to acetyl CoA for processing in the citric acid cycle

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17
Q

Which stage involves the degradation of fatty acids to acetyl CoA?
a) Stage 1 (mobilization)
b) Stage 2 (activation and transport)
c) Stage 3 (breakdown into acetyl CoA)
d) None of the above

A

c) Stage 3 (breakdown into acetyl CoA)

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17
Q

What occurs during Stage 1 of the processing of fatty acids as fuel?
a) Degradation of fatty acids to acetyl CoA
b) Mobilization of lipids, release from adipose tissue, and transport to energy-requiring tissues
c) Activation of fatty acids and transport into the mitochondria
d) Synthesis of triacylglycerols

A

b) Mobilization of lipids, release from adipose tissue, and transport to energy-requiring tissues

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18
Q

What catalyzes the hydrolysis of triacylglycerols to fatty acids during mobilization?
a) Hormones
b) Perilipin
c) Hormonally controlled lipases
d) Phosphorylation

A

c) Hormonally controlled lipases

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19
Q

Which proteins are phosphorylated by PKA upon activation of the 7TM receptor?
a) Perilipin and hormone-sensitive lipase
b) Phospholipase A2 and phosphatidic acid phosphatase
c) Apolipoprotein B-48 and chylomicrons
d) Sphingomyelinase and ceramide

A

a) Perilipin and hormone-sensitive lipase

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20
Q

What is the first step in the conversion of triacylglycerols into free fatty acids in response to hormonal signals?
a) Activation of protein kinase A
b) Phosphorylation of perilipin
c) Conversion of diacylglycerol into triacylglycerol
d) Release of monoacylglycerol

A

a) Activation of protein kinase A

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21
Q

What does protein kinase A phosphorylate in the process?
a) ATGL
b) Perilipin
c) Hormone-sensitive lipase
d) Monoacylglycerol lipase

A

b) Perilipin

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22
Q

What is the role of ATGL in the process?
a) It converts triacylglycerol into diacylglycerol.
b) It releases a fatty acid from diacylglycerol.
c) It completes the mobilization process.
d) It phosphorylates perilipin.

A

a) It converts triacylglycerol into diacylglycerol.

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23
Q

What is the product of the action of hormone-sensitive lipase on diacylglycerol?
a) Triacylglycerol
b) Monoacylglycerol
c) Fatty acid
d) Phosphatidic acid

A

c) Fatty acid

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24
Q

What enzyme completes the mobilization process by converting monoacylglycerol into free fatty acids?
a) Perilipin
b) Protein kinase A
c) Monoacylglycerol lipase
d) Hormone-sensitive lipase

A

c) Monoacylglycerol lipase

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25
Q

How are fatty acids transported in the blood during mobilization?
a) Through lipoproteins
b) Through albumin
c) Through cholesterol carriers
d) Through hemoglobin

A

b) Through albumin

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26
Q

What molecule transports fatty acids in the blood and has multiple binding sites for fatty acids?
a) Hemoglobin
b) Lipoproteins
c) Albumin
d) Hormones

A

c) Albumin

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27
Q

What happens to glycerol after it is released into the blood during mobilization?
a) It is oxidized to acetyl CoA.
b) It is stored in adipose tissue.
c) It is absorbed by the liver, phosphorylated, and oxidized to dihydroxyacetone phosphate.
d) It is transported to muscle tissues for energy production.

A

c) It is absorbed by the liver, phosphorylated, and oxidized to dihydroxyacetone phosphate.

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28
Q

How do fatty acids enter intestinal cells?
a) Through passive diffusion
b) Through facilitated diffusion by FATPs
c) Through active transport by FABPs
d) Through phagocytosis

A

b) Through facilitated diffusion by FATPs

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29
Q

What is the role of Acyl CoA synthetase in fatty acid activation?
a) It catalyzes the breakdown of fatty acids.
b) It transports fatty acids within the cell.
c) It converts fatty acids into triglycerides.
d) It catalyzes the formation of a thioester linkage to coenzyme A.

A

d) It catalyzes the formation of a thioester linkage to coenzyme A.

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30
Q

Where does the activation of fatty acids by Acyl CoA synthetase take place?
a) In the cytoplasm
b) On the inner mitochondrial membrane
c) On the outer mitochondrial membrane
d) In the endoplasmic reticulum

A

c) On the outer mitochondrial membrane

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31
Q

What is the first step in the activation of fatty acids by Acyl CoA synthetase?
a) Reaction of fatty acid and CoA
b) Reaction of fatty acid and AMP
c) Reaction of fatty acid and ATP, yielding acyl adenylate and pyrophosphate (PPi)
d) Reaction of fatty acid and water

A

c) Reaction of fatty acid and ATP, yielding acyl adenylate and pyrophosphate (PPi)

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32
Q

What is formed in the first step of fatty acid activation?
a) Acyl CoA and AMP
b) Acyl adenylate and CoA
c) Acyl CoA and pyrophosphate (PPi)
d) Acyl adenylate and pyrophosphate (PPi)

A

b) Acyl adenylate and CoA

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33
Q

What is the final product of the overall reaction catalyzed by Acyl CoA synthetase?
a) RCOO−
b) CoA
c) Acyl CoA
d) ATP

A

c) Acyl CoA

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34
Q

What is the role of carnitine in the transport of fatty acids into the mitochondrial matrix?
a) It transports fatty acids directly across the inner mitochondrial membrane.
b) It acts as a cofactor for fatty acid activation by Acyl CoA synthetase.
c) It conjugates with fatty acids to facilitate their transport across the inner mitochondrial membrane.
d) It catalyzes the breakdown of fatty acids.

A

c) It conjugates with fatty acids to facilitate their transport across the inner mitochondrial membrane.

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35
Q

How are fatty acids transported across the inner mitochondrial membrane?
a) By passive diffusion
b) By facilitated diffusion through channels
c) By conjugation with carnitine
d) By active transport

A

c) By conjugation with carnitine

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36
Q

Which enzyme catalyzes the transfer of the acyl group from acyl CoA to carnitine?
a) Carnitine synthase
b) Carnitine transporter
c) Carnitine acyltransferase I (CATI)
d) Carnitine acyltransferase II (CATII)

A

c) Carnitine acyltransferase I (CATI)

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37
Q

What is the role of acyl carnitine translocase in mitochondrial fatty acid transport?
a) It catalyzes the synthesis of acyl carnitine.
b) It shuttles acyl carnitine across the outer mitochondrial membrane.
c) It exchanges carnitine for acyl carnitine across the inner mitochondrial membrane.
d) It catalyzes the transfer of the acyl group from carnitine to coenzyme A.

A

c) It exchanges carnitine for acyl carnitine across the inner mitochondrial membrane.

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38
Q

Where does carnitine acyl-transferase II (CATII) catalyze the transfer of the acyl group?
a) On the outer mitochondrial membrane
b) On the cytoplasmic side of the inner mitochondrial membrane
c) On the matrix side of the inner mitochondrial membrane
d) In the cytoplasm

A

c) On the matrix side of the inner mitochondrial membrane

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39
Q

Why is the transfer of the acyl group from carnitine to coenzyme A thermodynamically feasible?
a) Because the reaction is exergonic.
b) Because the reaction is endergonic.
c) Because the O-acyl link in carnitine has a low group-transfer potential.
d) Because the O-acyl link in carnitine has a high group-transfer potential.

A

d) Because the O-acyl link in carnitine has a high group-transfer potential.

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40
Q

What symptoms are associated with carnitine deficiency?
a) Mild muscle cramping
b) Severe weakness
c) Death
d) All of the above

A

d) All of the above

41
Q

What specific organs are predominantly affected by carnitine deficiency?
a) Liver and lungs
b) Muscle, kidney, and heart
c) Brain and spleen
d) Skin and pancreas

A

b) Muscle, kidney, and heart

42
Q

What symptoms are characteristic of carnitine acyltransferase deficiency?
a) Seizures
b) Muscle weakness during prolonged exercise
c) Respiratory problems
d) Cognitive impairment

A

b) Muscle weakness during prolonged exercise

43
Q

What do diseases related to deficiencies of carnitine, transferase, or translocase demonstrate?
a) They demonstrate the importance of lipid metabolism in brain development.
b) They show that impaired flow of a metabolite between cellular compartments can lead to pathologies.
c) They indicate the role of cholesterol in muscle function.
d) They highlight the significance of protein synthesis in heart health.

A

b) They show that impaired flow of a metabolite between cellular compartments can lead to pathologies.

44
Q

What is the first step in the β-oxidation pathway?
a) Hydration
b) Oxidation by NAD+
c) Oxidation by FAD
d) Thiolysis by coenzyme A

A

c) Oxidation by FAD

45
Q

How many steps are there in the β-oxidation pathway?
a) Three
b) Four
c) Five
d) Six

A

b) Four

46
Q

Why is the pathway called the β-oxidation pathway?
a) Because oxidation occurs at the α-carbon atom
b) Because oxidation occurs at the γ-carbon atom
c) Because oxidation occurs at the β-carbon atom
d) Because oxidation occurs at the δ-carbon atom

A

c) Because oxidation occurs at the β-carbon atom

47
Q

Which enzyme oxidizes fatty acid chains containing from 12 to 18 carbon atoms?
a) Short-chain acyl CoA dehydrogenase
b) Medium-chain acyl CoA dehydrogenase
c) Long-chain acyl CoA dehydrogenase
d) Beta-oxidase

A

c) Long-chain acyl CoA dehydrogenase

48
Q

What is the substrate specificity of medium-chain acyl CoA dehydrogenase?
a) 4- and 6-carbon fatty acid chains
b) 4 to 14 carbon fatty acid chains
c) Fatty acid chains containing more than 18 carbon atoms
d) Fatty acid chains containing exactly 12 carbon atoms

A

b) 4 to 14 carbon fatty acid chains

49
Q

Which fatty acid chain lengths are oxidized by short-chain acyl CoA dehydrogenase?
a) 4- and 6-carbon fatty acid chains
b) 12 to 18 carbon fatty acid chains
c) 4 to 14 carbon fatty acid chains
d) Fatty acid chains containing more than 18 carbon atoms

A

a) 4- and 6-carbon fatty acid chains

50
Q

What is the complete reaction for one round of β-oxidation?
a) Cn -acyl CoA + FAD + NAD+ + H2O + CoA → Cn–2 -acyl CoA + FADH2 + NADH + acetyl CoA + H+
b) Palmitoyl CoA + 7 FAD + 7 NAD+ + 7 CoA + 7 H2O → 8 acetyl CoA + 7 FADH2 + 7 NADH + 7 H+
c) Palmitoyl CoA + FAD + NAD+ + H2O + CoA → Palmitate + FADH2 + NADH + acetyl CoA + H+
d) Cn -acyl CoA + FAD + NADH + H+ → Cn–2 -acyl CoA + FADH2 + NAD+ + acetyl CoA + H2O

A

b) Palmitoyl CoA + 7 FAD + 7 NAD+ + 7 CoA + 7 H2O → 8 acetyl CoA + 7 FADH2 + 7 NADH + 7 H+

51
Q

How many molecules of ATP are generated from the complete oxidation of palmitate?
a) 104
b) 106
c) 108
d) 110

A

b) 106

52
Q

How many molecules of ATP are consumed during palmitate activation?
a) 1
b) 2
c) 3
d) 4

A

b) 2

53
Q

Which transport mechanism is primarily responsible for transporting dietary fatty acids?
a) Albumin
b) VLDL
c) Chylomicrons
d) LDL

A

c) Chylomicrons

54
Q

What is the primary source of stored fatty acids?
a) Liver
b) Intestine
c) Adipocytes
d) Muscle cells

A

c) Adipocytes

55
Q

Which lipoprotein is primarily involved in transporting de novo synthesized fatty acids?
a) HDL
b) LDL
c) Chylomicrons
d) VLDL

A

d) VLDL

56
Q

What initiates the E2 elimination in the reaction catalyzed by Acyl CoA dehydrogenase?
a) FAD
b) NADH
c) A general base
d) Acetyl CoA

A

c) A general base

57
Q

What intermediate is formed during the reaction catalyzed by Acyl CoA dehydrogenase?
a) Keto intermediate
b) Enol intermediate
c) Alkene intermediate
d) Ester intermediate

A

b) Enol intermediate

58
Q

Which molecule picks up one electron during the reaction?
a) NADH
b) FAD
c) Acetyl CoA
d) Ubiquinone

A

b) FAD

59
Q

What is the ultimate fate of the electrons transferred to ETF?
a) They are used to reduce ubiquinone.
b) They are donated to an iron sulfur protein.
c) They form semiquinone.
d) They are transferred to NADH.

A

a) They are used to reduce ubiquinone.

60
Q

Why can’t β-oxidation alone degrade unsaturated fatty acids?
a) Unsaturated fatty acids have an odd number of carbons.
b) Unsaturated fatty acids lack acyl CoA dehydrogenase.
c) Unsaturated fatty acids form a unique intermediate not recognized by acyl CoA dehydrogenase.
d) Unsaturated fatty acids are too large to enter the mitochondria.

A

c) Unsaturated fatty acids form a unique intermediate not recognized by acyl CoA dehydrogenase.

61
Q

What is the role of cis-Δ3 -enoyl CoA isomerase in the degradation of monounsaturated fatty acids?
a) It converts cis-Δ3 -enoyl CoA to trans-Δ2 -enoyl CoA.
b) It converts trans-Δ2 -enoyl CoA to cis-Δ3 -enoyl CoA.
c) It hydrolyzes fatty acids.
d) It oxidizes fatty acids.

A

a) It converts cis-Δ3 -enoyl CoA to trans-Δ2 -enoyl CoA.

62
Q

What additional step is required for the degradation of unsaturated fatty acids with odd numbers of double bonds?
a) Conversion to cis-Δ3 -enoyl CoA
b) Conversion to trans-Δ2 -enoyl CoA
c) Isomerization
d) Hydroxylation

A

c) Isomerization

63
Q

Which enzymes are necessary for the complete oxidation of the diunsaturated fatty acid linoleate?
a) Acyl CoA dehydrogenase
b) Enoyl CoA isomerase and 2,4-dienoyl CoA reductase
c) Cis-∆3-enoyl CoA isomerase
d) Fatty acid synthase

A

b) Enoyl CoA isomerase and 2,4-dienoyl CoA reductase

64
Q

What is the role of cis-∆3-enoyl CoA isomerase in the oxidation of polyunsaturated fatty acids?
a) It converts cis-∆3-enoyl CoA to trans-∆2-enoyl CoA.
b) It shifts the double bond to the ∆2 position.
c) It oxidizes fatty acids.
d) It reduces fatty acids.

A

b) It shifts the double bond to the ∆2 position.

65
Q

What is the final product of odd-numbered fatty acid degradation?
a) Acetyl CoA
b) Succinyl CoA
c) Propionyl CoA
d) Malonyl CoA

A

c) Propionyl CoA

66
Q

How is propionyl CoA converted to succinyl CoA?
a) By direct conversion in one step
b) By decarboxylation
c) By carboxylation in a reaction driven by ATP hydrolysis
d) By reduction

A

c) By carboxylation in a reaction driven by ATP hydrolysis

67
Q

Which enzyme catalyzes the carboxylation of propionyl CoA?
a) Pyruvate carboxylase
b) Propionyl CoA carboxylase
c) Acetyl CoA carboxylase
d) Malonyl CoA decarboxylase

A

b) Propionyl CoA carboxylase

68
Q

What is the cofactor required for the conversion of L-methylmalonyl CoA to succinyl CoA?
a) Biotin
b) Vitamin B6
c) Vitamin B12
d) Folate

A

c) Vitamin B12

69
Q

Which element is bound to the corrin ring in cobalamin enzymes?
a) Cobalt
b) Iron
c) Magnesium
d) Zinc

A

a) Cobalt

70
Q

What type of reactions do cobalamin enzymes catalyze?
a) Hydrolysis
b) Oxidation
c) Intramolecular rearrangements, methylations, and deoxyribose formation
d) Polymerization

A

c) Intramolecular rearrangements, methylations, and deoxyribose formation

71
Q

What occupies the fifth position of the corrin ring?
a) Cyanide
b) Benzimidazole
c) Methyl
d) Deoxyadenosine

A

b) Benzimidazole

72
Q

What happens to the methylene group in coenzyme B12?
a) It forms a stable bond with the corrin ring.
b) It is hydrolyzed.
c) It undergoes homolytic bond cleavage to form a very reactive radical.
d) It is methylated.

A

c) It undergoes homolytic bond cleavage to form a very reactive radical.

73
Q

What initiates the mechanism of methylmalonyl CoA mutase?
a) Extraction of a hydrogen from the substrate
b) Migration of the CO-S-CoA group
c) Creation of a 5’-deoxyadenosyl radical by the Co+3 ion
d) Recovery of hydrogen from 5’-deoxyadenosine

A

c) Creation of a 5’-deoxyadenosyl radical by the Co+3 ion

74
Q

What role does the 5’-deoxyadenosyl radical play in the mechanism?
a) It rearranges the substrate radical.
b) It migrates the CO-S-CoA group.
c) It recovers hydrogen from the substrate.
d) It extracts a hydrogen from the substrate.

A

d) It extracts a hydrogen from the substrate.

75
Q

What happens to the CO-S-CoA group during the mechanism?
a) It forms a stable bond with the substrate.
b) It migrates to another position.
c) It is hydrolyzed.
d) It is reduced.

A

b) It migrates to another position.

76
Q

What is the primary function of peroxisomes in cells?
a) Synthesizing fatty acids
b) Storing toxic substances
c) Breaking down toxic substances
d) Transporting proteins

A

c) Breaking down toxic substances

77
Q

Which types of fatty acids are primarily oxidized in peroxisomes?
a) Short-chain fatty acids
b) Medium-chain fatty acids
c) Very long (> 22C) and branched fatty acids
d) Saturated fatty acids

A

c) Very long (> 22C) and branched fatty acids

78
Q

What is the final product of fatty acid oxidation in peroxisomes?
a) Acetyl CoA
b) Octanoyl-CoA
c) Malonyl CoA
d) Phytanic acid

A

b) Octanoyl-CoA

79
Q

What is the role of peroxisome acyl CoA dehydrogenase in fatty acid oxidation?
a) Transfer of electrons from FADH2 to O2
b) Transfer of electrons from substrate to FADH2 to O2
c) Hydrolysis of fatty acids
d) Conversion of fatty acids to triglycerides

A

b) Transfer of electrons from substrate to FADH2 to O2

80
Q

What is the consequence of peroxisome deficiency?
a) Cardiovascular diseases
b) Neurodegenerative diseases (Zellweger Spectrum, ZS)
c) Liver diseases
d) Respiratory diseases

A

b) Neurodegenerative diseases (Zellweger Spectrum, ZS)

81
Q

What is the primary reason for the formation of ketone bodies from acetyl CoA in the liver?
a) Excess glucose in the bloodstream
b) Oxaloacetate limitation in the citric acid cycle
c) Insulin resistance
d) High levels of glucagon

A

b) Oxaloacetate limitation in the citric acid cycle

82
Q

Which enzyme catalyzes the condensation of two molecules of acetyl CoA to form acetoacetyl CoA?
a) Thiolase
b) Acetyl CoA synthetase
c) Acetyl CoA carboxylase
d) Acetyltransferase

A

a) Thiolase

83
Q

What is the final product of the three-step process for the formation of ketone bodies?
a) Acetone
b) Acetoacetate
c) Acetyl CoA
d) Acetylacetone

A

b) Acetoacetate

84
Q

How many molecules of acetyl CoA are required to produce one molecule of acetoacetate?
a) 1
b) 2
c) 3
d) 4

A

b) 2

85
Q

In what condition is the formation of ketone bodies commonly observed?
a) During high-carbohydrate intake
b) During intense physical activity
c) During fasting or starvation
d) During protein-rich meals

A

c) During fasting or starvation

86
Q

Which compound is oxidized back to acetoacetate during the utilization of ketone bodies?
a) Acetoacetate
b) D-3-hydroxybutyrate
c) Succinyl CoA
d) Acetoacetyl CoA

A

b) D-3-hydroxybutyrate

87
Q

How is acetoacetate activated for utilization in other tissues?
a) By reacting with acetyl CoA
b) By reacting with succinyl CoA
c) By reacting with oxaloacetate
d) By reacting with citrate

A

b) By reacting with succinyl CoA

88
Q

What compound is formed when acetoacetate reacts with succinyl CoA?
a) D-3-hydroxybutyrate
b) Acetoacetyl CoA
c) Acetyl CoA
d) Succinyl CoA

A

c) Acetyl CoA

89
Q

Which metabolic pathway does acetyl CoA enter after its conversion from acetoacetyl CoA?
a) Glycolysis
b) Pentose phosphate pathway
c) Citric acid cycle
d) Gluconeogenesis

A

c) Citric acid cycle

90
Q

What is the primary purpose of utilizing ketone bodies in other tissues?
a) To generate ATP
b) To store energy
c) To reduce blood glucose levels
d) To increase blood insulin levels

A

a) To generate ATP

91
Q

Which cells primarily utilize ketone bodies as fuel?
a) Liver cells
b) Skeletal muscle cells
c) Heart and renal cells
d) Adipose cells

A

c) Heart and renal cells

92
Q

Why is the brain able to switch to ketone bodies as its main fuel?
a) Ketone bodies are more readily available than glucose.
b) Ketone bodies are a more efficient source of energy for the brain.
c) Glucose availability decreases during fasting or starvation.
d) Brain cells can synthesize ketone bodies from fatty acids.

A

c) Glucose availability decreases during fasting or starvation.

93
Q

What is the primary advantage of ketone bodies being water-soluble forms of acetyl groups?
a) They can be stored efficiently in adipose tissue.
b) They can be transported easily in the bloodstream.
c) They can only be utilized by specific tissues.
d) They can be converted directly into glucose

A

b) They can be transported easily in the bloodstream.

94
Q

How is acetone, a byproduct of ketone body metabolism, typically handled by the body?
a) It is stored in the liver for later use.
b) It is converted into glucose.
c) It is excreted from the body.
d) It is recycled back into ketone bodies.

A

c) It is excreted from the body.

95
Q

Which medical condition has been shown to benefit from a ketogenic diet?
a) Type 2 diabetes
b) Hypertension
c) Epilepsy
d) Osteoporosis

A

c) Epilepsy

96
Q

What is the primary reason for the production of ketone bodies in diabetic ketosis?
a) Impaired liver function
b) Increased levels of insulin
c) Lack of glucose absorption by the liver
d) Excessive intake of dietary fats

A

c) Lack of glucose absorption by the liver

97
Q

How does the lack of oxaloacetate affect the utilization of acetyl CoA in the citric acid cycle?
a) It enhances the utilization of acetyl CoA.
b) It inhibits the citric acid cycle.
c) It promotes the conversion of acetyl CoA to ketone bodies.
d) It has no effect on the citric acid cycle.

A

b) It inhibits the citric acid cycle.

98
Q

What role do ketone bodies play in diabetic ketosis?
a) They promote glucose absorption by the liver.
b) They compete with glucose for utilization in other tissues.
c) They enhance insulin signaling.
d) They inhibit fatty acid synthesis

A

b) They compete with glucose for utilization in other tissues.

99
Q

What happens to blood pH levels when ketone bodies accumulate in high levels?
a) Blood pH increases.
b) Blood pH decreases.
c) Blood pH remains unchanged.
d) Blood pH becomes alkaline.

A

b) Blood pH decreases.

100
Q

Which condition is associated with impaired insulin signaling leading to diabetic ketosis?
a) Type I diabetes
b) Type II diabetes
c) Hypertension
d) Hyperthyroidism

A

a) Type I diabetes

101
Q
A

biochem 2 (6 decks)

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