Question 1

All are true for 2,4-dienoyl-CoA reductase EXCEPT:

Accepted Answer

A)  reduces trans-Δ2, cis-Δ4 double bonds to trans-Δ3. 
B)  uses NADPH. 
C)  involved in saturated fatty acid catabolism. 
D)  cooperates with β-oxidation in fatty acid oxidation. 
E)  all are true. 
A)  reduces trans-Δ2, cis-Δ4 double bonds to trans-Δ3. 
B)  uses NADPH. 
C)  involved in saturated fatty acid catabolism. 
D)  cooperates with β-oxidation in fatty acid oxidation. 
E)  all are true. C

Question 2

How many NADH are generated from the complete oxidation of palmitoyl-CoA to CO2?

Accepted Answer

A)  7 from β-oxidation and 24 from the TCA. 
B)  8 from β-oxidation and 24 from the TCA 
C)  7 from β-oxidation and 21 from the TCA 
D)  7 from β-oxidation and 28 from the TCA 
E)  8 from β-oxidation and 24 from the TCA. 
A)  7 from β-oxidation and 24 from the TCA. 
B)  8 from β-oxidation and 24 from the TCA 
C)  7 from β-oxidation and 21 from the TCA 
D)  7 from β-oxidation and 28 from the TCA 
E)  8 from β-oxidation and 24 from the TCA. A

Question 3

Fatty acids are mobilized from adipose cells in response to all of the hormones EXCEPT:

Accepted Answer

A)  ACTH (adrenocorticotropic hormone). 
B)  glucagon. 
C)  insulin. 
D)  epinephrine (adrenaline). 
E)  all are true. 
A)  ACTH (adrenocorticotropic hormone). 
B)  glucagon. 
C)  insulin. 
D)  epinephrine (adrenaline). 
E)  all are true. C

Question 4

Ketone body carbons enter the major metabolic pathways of the cells by conversion to:

Accepted Answer

A)  acetyl-CoA. 
B)  butyrate. 
C)  citrate. 
D)  pyruvate. 
E)  glucose-6-phosphate. 
A)  acetyl-CoA. 
B)  butyrate. 
C)  citrate. 
D)  pyruvate. 
E)  glucose-6-phosphate.

Question 5

Bile salts are important in the initial digestion of triacylglycerols in the intestine because they:

Accepted Answer

A)  are coenzymes for pancreatic lipase. 
B)  convert the inactive lipase into the active form. 
C)  emulsify the triacylglycerol globules to produce greater surface area which will increase the activity of the lipase. 
D)  activate the cleavage at the C-2 position. 
E)  permit greater permeability of the triacylglycerols through the intestinal membrane. 
A)  are coenzymes for pancreatic lipase. 
B)  convert the inactive lipase into the active form. 
C)  emulsify the triacylglycerol globules to produce greater surface area which will increase the activity of the lipase. 
D)  activate the cleavage at the C-2 position. 
E)  permit greater permeability of the triacylglycerols through the intestinal membrane.

Question 6

How many NAD+ are reduced in the β-oxidation of stearoyl-CoA to form nine molecules of acetyl-CoA?

Accepted Answer

A)  18 
B)  16 
C)  12 
D)  9 
E)  8 
A)  18 
B)  16 
C)  12 
D)  9 
E)  8

Question 7

The first three reactions of β-oxidation of saturated fatty acids are analogous to which sequence of metabolic reactions already discussed?

Accepted Answer

A)  succinate → fumarate → malate → oxaloacetate 
B)  isocitrate → α-ketoglutarate → succinate → fumarate 
C)  oxaloacetate → citrate → isocitrate → α-ketoglutarate 
D)  phosphoenolpyruvate → pyruvate → acetyl-CoA → citrate 
E)  α-ketoglutarate → succinyl-CoA → succinate → fumarate 
A)  succinate → fumarate → malate → oxaloacetate 
B)  isocitrate → α-ketoglutarate → succinate → fumarate 
C)  oxaloacetate → citrate → isocitrate → α-ketoglutarate 
D)  phosphoenolpyruvate → pyruvate → acetyl-CoA → citrate 
E)  α-ketoglutarate → succinyl-CoA → succinate → fumarate

Question 8

In ketone body biosynthesis, the HMG-CoA lyase is mechanistically the reverse of the first half of the reaction catalyzed by:

Accepted Answer

A)  aconitase. 
B)  β-hydroxybutyrate dehydrogenase. 
C)  citrate synthase. 
D)  pyruvate dehydrogenase. 
E)  succinyl-CoA synthase. 
A)  aconitase. 
B)  β-hydroxybutyrate dehydrogenase. 
C)  citrate synthase. 
D)  pyruvate dehydrogenase. 
E)  succinyl-CoA synthase.

Question 9

The product of β-oxidation, acetyl-CoA, can be used for all EXCEPT:

Accepted Answer

A)  synthesis of ketone bodies. 
B)  synthesis of amino acids. 
C)  catabolism in the TCA cycle. 
D)  synthesis of glucose. 
E)  none of the above. 
A)  synthesis of ketone bodies. 
B)  synthesis of amino acids. 
C)  catabolism in the TCA cycle. 
D)  synthesis of glucose. 
E)  none of the above.

Question 10

Which of the following statements regarding ketone bodies is true?

Accepted Answer

A)  They are made in the liver as a result of excessive fatty acid oxidation 
B)  While normally used by muscle tissue, under starvation conditions, they are used by the brain and red blood cells 
C)  Excessive levels of β-hydroxybutyrate in the blood stream will result in an increase of the blood pH 
D)  Acetone is used as a fuel in the muscle by first undergoing isomerization followed by oxidation to propionyl CoA 
E)  Both A and B are correct 
A)  They are made in the liver as a result of excessive fatty acid oxidation 
B)  While normally used by muscle tissue, under starvation conditions, they are used by the brain and red blood cells 
C)  Excessive levels of β-hydroxybutyrate in the blood stream will result in an increase of the blood pH 
D)  Acetone is used as a fuel in the muscle by first undergoing isomerization followed by oxidation to propionyl CoA 
E)  Both A and B are correct

Question 11

Ketone bodies are synthesized in the:

Accepted Answer

A)  cytosol of muscle. 
B)  mitochondria of liver. 
C)  endoplasmic reticulum of heart. 
D)  plasma membrane of brain. 
E)  none of the above. 
A)  cytosol of muscle. 
B)  mitochondria of liver. 
C)  endoplasmic reticulum of heart. 
D)  plasma membrane of brain. 
E)  none of the above.

Question 12

Absorbed lipids are condensed with glycerol in the epithelial cells into ____ and re-packaged into ____ that are initially transported by the ____ system.

Accepted Answer

A)  phospholipids; VLDL; lymphatic 
B)  triacylglycerols; VLDL; portal 
C)  triacylglycerols; LDL; portal 
D)  triacylglycerols; chylomicron; lymphatic 
E)  triacylglycerols; VLDL; lymphatic 
A)  phospholipids; VLDL; lymphatic 
B)  triacylglycerols; VLDL; portal 
C)  triacylglycerols; LDL; portal 
D)  triacylglycerols; chylomicron; lymphatic 
E)  triacylglycerols; VLDL; lymphatic

Question 13

All are characteristics of acyl-CoA dehydrogenase EXCEPT:

Accepted Answer

A)  oxidation of the Cα-Cβ bond. 
B)  comes in at least three isozymes each specific for fatty acids of differing chain lengths. 
C)  uses tightly bound FAD. 
D)  electrons are transferred to electron transfer flavoprotein (ETF) and on to Q of the electron transport system. 
E)  all are correct. 
A)  oxidation of the Cα-Cβ bond. 
B)  comes in at least three isozymes each specific for fatty acids of differing chain lengths. 
C)  uses tightly bound FAD. 
D)  electrons are transferred to electron transfer flavoprotein (ETF) and on to Q of the electron transport system. 
E)  all are correct.

Question 14

What are the three most common ketone bodies?

Accepted Answer

A)  acetone, butyrate and acetyl-CoA 
B)  acetoacetate, hydroxyacetone phosphate and butyrate 
C)  acetone, β-hydroxybutyrate and acetoacetate 
D)  acetoacetate, acetyl-CoA and acetone 
E)  butyrate, acetoacetate and acetone 
A)  acetone, butyrate and acetyl-CoA 
B)  acetoacetate, hydroxyacetone phosphate and butyrate 
C)  acetone, β-hydroxybutyrate and acetoacetate 
D)  acetoacetate, acetyl-CoA and acetone 
E)  butyrate, acetoacetate and acetone

Question 15

Enoyl-CoA hydratase belongs to what class of enzymes?

Accepted Answer

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

Question 16

How are long chain fatty acid derivatives transferred into the mitochondrial matrix?​

Accepted Answer

​Long-chain fatty acyl-CoA derivatives c

Question 17

Chylomicrons:

Accepted Answer

A)  are formed in adipose tissue. 
B)  are primary energy sources for the brain. 
C)  transport dietary triacylglycerols through the bloodstream. 
D)  are formed in and secreted by the liver. 
E)  contain more phospholipid than triacylglycerol molecules. 
A)  are formed in adipose tissue. 
B)  are primary energy sources for the brain. 
C)  transport dietary triacylglycerols through the bloodstream. 
D)  are formed in and secreted by the liver. 
E)  contain more phospholipid than triacylglycerol molecules.

Question 18

Which of the following correctly explains the distribution of lipids from the diet?

Accepted Answer

A)  All dietary lipids are all packaged into chylomicrons 
B)  Dietary triacylglycerols are packaged into chylomicrons while dietary cholesterol is packaged into low density lipoproteins 
C)  Dietary lipids are packaged into very low density lipoproteins which lose triacylglycerol to become low density lipoproteins 
D)  Dietary lipids are packaged into low density lipoproteins which lose cholesterol to become very low density lipoproteins 
E)  None of the above 
A)  All dietary lipids are all packaged into chylomicrons 
B)  Dietary triacylglycerols are packaged into chylomicrons while dietary cholesterol is packaged into low density lipoproteins 
C)  Dietary lipids are packaged into very low density lipoproteins which lose triacylglycerol to become low density lipoproteins 
D)  Dietary lipids are packaged into low density lipoproteins which lose cholesterol to become very low density lipoproteins 
E)  None of the above

Question 19

How many NADH can be produced by the complete oxidation of β-hydroxybutyrate? The conversion of a molecule of β-hydroxybutyrate to 2 molecules of acetyl CoA produces 1 NADH.

Accepted Answer

A)  3 
B)  4 
C)  6 
D)  7 
E)  9 
A)  3 
B)  4 
C)  6 
D)  7 
E)  9

Question 20

For the complete oxidation of a saturated fatty acid with 16 carbons, how many times must the β-oxidation cycle be repeated?

Accepted Answer

A)  4 
B)  7 
C)  8 
D)  6 
E)  16 
A)  4 
B)  7 
C)  8 
D)  6 
E)  16

Exam 23: Fatty Acid Catabolism

All are true for 2,4-dienoyl-CoA reductase EXCEPT:

How many NADH are generated from the complete oxidation of palmitoyl-CoA to CO2?

Fatty acids are mobilized from adipose cells in response to all of the hormones EXCEPT:

Ketone body carbons enter the major metabolic pathways of the cells by conversion to:

Bile salts are important in the initial digestion of triacylglycerols in the intestine because they:

How many NAD+ are reduced in the β-oxidation of stearoyl-CoA to form nine molecules of acetyl-CoA?

The first three reactions of β-oxidation of saturated fatty acids are analogous to which sequence of metabolic reactions already discussed?

In ketone body biosynthesis, the HMG-CoA lyase is mechanistically the reverse of the first half of the reaction catalyzed by:

The product of β-oxidation, acetyl-CoA, can be used for all EXCEPT:

Which of the following statements regarding ketone bodies is true?

Ketone bodies are synthesized in the:

Absorbed lipids are condensed with glycerol in the epithelial cells into ____ and re-packaged into ____ that are initially transported by the ____ system.

All are characteristics of acyl-CoA dehydrogenase EXCEPT:

What are the three most common ketone bodies?

Enoyl-CoA hydratase belongs to what class of enzymes?

How are long chain fatty acid derivatives transferred into the mitochondrial matrix?​

Chylomicrons:

Which of the following correctly explains the distribution of lipids from the diet?

How many NADH can be produced by the complete oxidation of β-hydroxybutyrate? The conversion of a molecule of β-hydroxybutyrate to 2 molecules of acetyl CoA produces 1 NADH.

For the complete oxidation of a saturated fatty acid with 16 carbons, how many times must the β-oxidation cycle be repeated?

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

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

The Reception and Transmission of Extracellular Information

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How many NADH are generated from the complete oxidation of palmitoyl-CoA to CO₂?

How many NAD⁺ are reduced in the β-oxidation of stearoyl-CoA to form nine molecules of acetyl-CoA?

Absorbed lipids are condensed with glycerol in the epithelial cells into and re-packaged into that are initially transported by the system.

How are long chain fatty acid derivatives transferred into the mitochondrial matrix?