Question 1

The theoretical P/O ratio for the oxidation of a fatty acid to acetyl-CoA is

Accepted Answer

A)  3.0 
B)  2.5 
C)  2.0 
D)  0.25 
E)  0 
A)  3.0 
B)  2.5 
C)  2.0 
D)  0.25 
E)  0

Question 2

The fatty acids carried in the blood by serum albumin under fasting conditions are most likely derived from the action of

Accepted Answer

A)  fatty acid synthase. 
B)  hormone sensitive lipase. 
C)  pancreatic lipase. 
D)  lipoprotein lipase. 
E)  cholesterol esterase. 
A)  fatty acid synthase. 
B)  hormone sensitive lipase. 
C)  pancreatic lipase. 
D)  lipoprotein lipase. 
E)  cholesterol esterase.

Question 3

Medium-chain triacylglycerols may be an appropriate dietary supplement for an individual with a deficiency of

Accepted Answer

A)  albumin in blood. 
B)  carnitine in skeletal muscle. 
C)  fatty acid oxidation in cardiac muscle. 
D)  hormone?sensitive lipase in adipose. 
E)  low density lipoprotein in blood. 
A)  albumin in blood. 
B)  carnitine in skeletal muscle. 
C)  fatty acid oxidation in cardiac muscle. 
D)  hormone?sensitive lipase in adipose. 
E)  low density lipoprotein in blood.

Question 4

In mammalian fatty acid synthase, malonyl CoA provides a malonyl group which:

Accepted Answer

A)  Covalently attaches to a serine hydroxyl group at a site on one subunit of the enzyme and is then transferred to the -SH of a phosphopantetheinyl group of the acyl carrier protein on the second subunit of the enzyme. 
B)  Covalently attaches to a serine hydroxyl group at a site on one subunit of the enzyme and is then transferred to the -SH of a cysteine group of the condensing enzyme domain on the same subunit of the enzyme. 
C)  Both 
D)  Neither 
A)  Covalently attaches to a serine hydroxyl group at a site on one subunit of the enzyme and is then transferred to the -SH of a phosphopantetheinyl group of the acyl carrier protein on the second subunit of the enzyme. 
B)  Covalently attaches to a serine hydroxyl group at a site on one subunit of the enzyme and is then transferred to the -SH of a cysteine group of the condensing enzyme domain on the same subunit of the enzyme. 
C)  Both 
D)  Neither

Question 5

The biosynthesis of triacylglycerols in adipose requires

Accepted Answer

A)  decreased activation of long?chain fatty acids. 
B)  decreased levels of plasma leptin. 
C)  increased glycerol secretion from adipose. 
D)  increased glucose uptake by adipose. 
E)  increased levels of plasma glucagon. 
A)  decreased activation of long?chain fatty acids. 
B)  decreased levels of plasma leptin. 
C)  increased glycerol secretion from adipose. 
D)  increased glucose uptake by adipose. 
E)  increased levels of plasma glucagon.

Question 6

The enzyme that catalyzes the reaction: Acetoacetate + Succinyl-CoA  Acetoacetyl-CoA + Succinate is essentially absent in the

Accepted Answer

A)  liver. 
B)  cardiac muscle. 
C)  striated muscle. 
D)  brain. 
E)  kidney 
A)  liver. 
B)  cardiac muscle. 
C)  striated muscle. 
D)  brain. 
E)  kidney

Question 7

During the biosynthesis of saturated fatty acids, the addition of every two-carbon unit requires

Accepted Answer

A)  2 NADH + 2 H+ + 1 ATP 
B)  2 NADPH + 2 H+ + 1 ATP 
C)  1 NADPH + H+ + 1 ATP 
D)  1 NADH + H+ + 1 FADH2 + 1 ATP 
E)  1 NADPH + H+ + 1 FADH2 + 1 ATP 
A)  2 NADH + 2 H+ + 1 ATP 
B)  2 NADPH + 2 H+ + 1 ATP 
C)  1 NADPH + H+ + 1 ATP 
D)  1 NADH + H+ + 1 FADH2 + 1 ATP 
E)  1 NADPH + H+ + 1 FADH2 + 1 ATP

Question 8

The steps of beta-oxidation parallel portions of:

Accepted Answer

A)  Gluconeogenesis 
B)  Glycolysis 
C)  Krebs cycle 
D)  Oxidative phosphorylation 
E)  Pentose phosphate shunt 
A)  Gluconeogenesis 
B)  Glycolysis 
C)  Krebs cycle 
D)  Oxidative phosphorylation 
E)  Pentose phosphate shunt

Question 9

Glycerol 3-phosphate in adipose tissue arises primarily from

Accepted Answer

A)  reduction of dihydroxyacetone phosphate. 
B)  hydrolysis of phosphatidic acid. 
C)  phosphorylation of glycerol by glycerokinase. 
D)  selective uptake from blood. 
E)  reduction of glyceraldehyde 3-phosphate. 
A)  reduction of dihydroxyacetone phosphate. 
B)  hydrolysis of phosphatidic acid. 
C)  phosphorylation of glycerol by glycerokinase. 
D)  selective uptake from blood. 
E)  reduction of glyceraldehyde 3-phosphate.

Question 10

All of the following conditions or factors would promote de novo fatty acid synthesis EXCEPT

Accepted Answer

A)  a hypercaloric-high protein diet. 
B)  low plasma levels of free fatty acids. 
C)  a high glucagon/insulin ratio. 
D)  high intracellular levels of citrate. 
E)  a hypercaloric-high carbohydrate diet. 
A)  a hypercaloric-high protein diet. 
B)  low plasma levels of free fatty acids. 
C)  a high glucagon/insulin ratio. 
D)  high intracellular levels of citrate. 
E)  a hypercaloric-high carbohydrate diet.

Question 11

In order for acetoacetate to be utilized by extrahepatic tissues, which of the following reactions must occur?

Accepted Answer

A)  decarboxylation of acetoacetate to form acetone 
B)  carboxylation of acetoacetate 
C)  reduction to beta-hydroxybutyrate 
D)  transfer of a coenzyme A from succinyl CoA to form acetoacetyl CoA 
E)  condensation with acetyl CoA to form HMG CoA 
A)  decarboxylation of acetoacetate to form acetone 
B)  carboxylation of acetoacetate 
C)  reduction to beta-hydroxybutyrate 
D)  transfer of a coenzyme A from succinyl CoA to form acetoacetyl CoA 
E)  condensation with acetyl CoA to form HMG CoA

Question 12

The sequence of reactions for the beta-oxidation of fatty acids is

Accepted Answer

A)  activation, dehydrogenation, hydration, dehydrogenation and cleavage. 
B)  activation, hydrogenation, dehydrogenation and cleavage. 
C)  activation, oxidation, dehydrogenation, hydration and cleavage. 
D)  activation, dehydrogenation, hydration and cleavage. 
E)  activation, hydrogenation, hydration, hydrogenation and cleavage. 
A)  activation, dehydrogenation, hydration, dehydrogenation and cleavage. 
B)  activation, hydrogenation, dehydrogenation and cleavage. 
C)  activation, oxidation, dehydrogenation, hydration and cleavage. 
D)  activation, dehydrogenation, hydration and cleavage. 
E)  activation, hydrogenation, hydration, hydrogenation and cleavage.

Question 13

An intermediate produced during the oxidation of palmitic acid to carbon dioxide and water in skeletal muscle mitochondria is

Accepted Answer

A)  pyruvic acid. 
B)  malonyl-CoA. 
C)  hydroxymethyl-glutaryl-CoA 
D)  acetoacetyl-CoA. 
E)  propionyl-CoA. 
A)  pyruvic acid. 
B)  malonyl-CoA. 
C)  hydroxymethyl-glutaryl-CoA 
D)  acetoacetyl-CoA. 
E)  propionyl-CoA.

Question 14

Fatty acids with an odd number of carbon atoms and certain branched-chain fatty acids can support the net synthesis of glucose because they

Accepted Answer

A)  increase the NAD/NADH ratio. 
B)  can produce methylmalonyl-CoA which is converted to succinyl-CoA. 
C)  are converted to malonyl-CoA. 
D)  yield NADPH on oxidation. 
E)  are converted to acetoacetate and beta-hydroxybutyrate. 
A)  increase the NAD/NADH ratio. 
B)  can produce methylmalonyl-CoA which is converted to succinyl-CoA. 
C)  are converted to malonyl-CoA. 
D)  yield NADPH on oxidation. 
E)  are converted to acetoacetate and beta-hydroxybutyrate.

Question 15

Which of the following molecules possesses a phosphopantetheine group?

Accepted Answer

A)  Acetyl CoA 
B)  Acyl carrier protein 
C)  Both 
D)  Neither 
A)  Acetyl CoA 
B)  Acyl carrier protein 
C)  Both 
D)  Neither

Question 16

With respect to the complete oxidation of fatty acids, as the degree of unsaturation increases the yield of ATP

Accepted Answer

A)  is constant. 
B)  slightly decreases. 
C)  slightly increases. 
D)  reaches a maximum with three double bonds. 
E)  depends upon the tissue. 
A)  is constant. 
B)  slightly decreases. 
C)  slightly increases. 
D)  reaches a maximum with three double bonds. 
E)  depends upon the tissue.

Question 17

A deficiency of carnitine would be expected to interfere with which of the following?

Accepted Answer

A)  Beta oxidation of long chain fatty acids. 
B)  Transport of fatty acids into adipose cells. 
C)  The synthesis of palmitate. 
D)  Mobilization of stored triacylglycerols from adipose tissue. 
E)  oxidation of ethanol to acetic acid. 
A)  Beta oxidation of long chain fatty acids. 
B)  Transport of fatty acids into adipose cells. 
C)  The synthesis of palmitate. 
D)  Mobilization of stored triacylglycerols from adipose tissue. 
E)  oxidation of ethanol to acetic acid.

Question 18

What is the main function of beta-oxidation?

Accepted Answer

A)  production of carbon dioxide. 
B)  provides NADPH. 
C)  degradation of fatty acids. 
D)  the main source of odd chain fatty acids. 
E)  important in membrane structure. 
A)  production of carbon dioxide. 
B)  provides NADPH. 
C)  degradation of fatty acids. 
D)  the main source of odd chain fatty acids. 
E)  important in membrane structure.

Question 19

The rate-limiting step of fatty acid synthesis is catalyzed by

Accepted Answer

A)  pyruvate dehydrogenase. 
B)  citrate-cleavage enzyme. 
C)  malic enzyme. 
D)  acetyl-CoA carboxylase. 
E)  thiolase. 
A)  pyruvate dehydrogenase. 
B)  citrate-cleavage enzyme. 
C)  malic enzyme. 
D)  acetyl-CoA carboxylase. 
E)  thiolase.

Question 20

Enzymes for the synthesis of oleic acid from palmitic acid are located in the

Accepted Answer

A)  cytosol. 
B)  endoplasmic reticulum. 
C)  mitochondria. 
D)  lysosomes. 
E)  Golgi apparatus. 
A)  cytosol. 
B)  endoplasmic reticulum. 
C)  mitochondria. 
D)  lysosomes. 
E)  Golgi apparatus.

Exam 17: Lipid Metabolism I: Synthesis, Storage, and Utilization of Fatty Acids and Triacylglycerols

The theoretical P/O ratio for the oxidation of a fatty acid to acetyl-CoA is

The fatty acids carried in the blood by serum albumin under fasting conditions are most likely derived from the action of

Medium-chain triacylglycerols may be an appropriate dietary supplement for an individual with a deficiency of

In mammalian fatty acid synthase, malonyl CoA provides a malonyl group which:

The biosynthesis of triacylglycerols in adipose requires

The enzyme that catalyzes the reaction: Acetoacetate + Succinyl-CoA <----> Acetoacetyl-CoA + Succinate is essentially absent in the

During the biosynthesis of saturated fatty acids, the addition of every two-carbon unit requires

The steps of beta-oxidation parallel portions of:

Glycerol 3-phosphate in adipose tissue arises primarily from

All of the following conditions or factors would promote de novo fatty acid synthesis EXCEPT

In order for acetoacetate to be utilized by extrahepatic tissues, which of the following reactions must occur?

The sequence of reactions for the beta-oxidation of fatty acids is

An intermediate produced during the oxidation of palmitic acid to carbon dioxide and water in skeletal muscle mitochondria is

Fatty acids with an odd number of carbon atoms and certain branched-chain fatty acids can support the net synthesis of glucose because they

Which of the following molecules possesses a phosphopantetheine group?

With respect to the complete oxidation of fatty acids, as the degree of unsaturation increases the yield of ATP

A deficiency of carnitine would be expected to interfere with which of the following?

What is the main function of beta-oxidation?

The rate-limiting step of fatty acid synthesis is catalyzed by

Enzymes for the synthesis of oleic acid from palmitic acid are located in the

Eukaryotic Cell Structure

DNA and RNA: Composition and Structure

Protein I: Composition and Structure

DNA Replication, Recombination, and Repair

RNA: Transcription and Rna Processing

Protein Synthesis: Translation and Posttranslational Modifications

Recombinant Dna and Biotechnology

Regulation of Gene Expression

Protein II: Structure-Function Relationships in Protein Families

Enzymes: Classification, Kinetics, and Control

The Cytochromes P450 and Nitric Oxide Synthases

Biological Membranes: Structure and Membrane Transport

Fundamentals of Signal Transduction

Bioenergetics and Oxidative Metabolism

Carbohydrate Metabolism I: Major Metabolic Pathways and Their Control

Carbohydrate Metabolism II: Special Pathways and Glycoconjugates

Lipid Metabolism II: Pathways of Metabolism of Special Lipids

Amino Acid Metabolism

Purine and Pyrimidine Nucleotide Metabolism

Metabolic Interrelationships

Biochemistry of Hormones

Molecular Cell Biology

Cell Cycle, Programmed Cell Death, and Cancer

Digestion and Absorption of Basic Nutritional Constituents

Digestion and Absorption of Basic Nutritional Constituents

Principles of Nutrition I and II

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