Question 1

The first true steroid synthesized in the steroid pathway is the following:

Accepted Answer

A)  Cholesterol. 
B)  Squalene 
C)  Lanosterol 
D)  Progesterone 
E)  Mevalonic acid 
A)  Cholesterol. 
B)  Squalene 
C)  Lanosterol 
D)  Progesterone 
E)  Mevalonic acid

Question 2

The oxidation of an unsaturated fatty acid leads to the production of fewer ATPs than a saturated fatty acid with the same number of carbons because ____

Accepted Answer

A)  the oxidation of the fatty acid stops when it reaches the double bond 
B)  unsaturated fatty acids cannot be metabolized 
C)  the double bond results in the bypassing of the first oxidation step of the pathway, thereby eliminating one FADH product 
D)  none of these 
A)  the oxidation of the fatty acid stops when it reaches the double bond 
B)  unsaturated fatty acids cannot be metabolized 
C)  the double bond results in the bypassing of the first oxidation step of the pathway, thereby eliminating one FADH product 
D)  none of these

Question 3

A key intermediate in the catabolism of fatty acids with uneven numbers of carbon atoms is

Accepted Answer

A)  malonyl-CoA 
B)  propionyl-CoA 
C)  oxaloacetate 
D)  phosphoenolpyruvate 
A)  malonyl-CoA 
B)  propionyl-CoA 
C)  oxaloacetate 
D)  phosphoenolpyruvate

Question 4

Which of the following enzyme types is involved in both fatty acid synthesis and breakdown?

Accepted Answer

A)  Carboxylase. 
B)  Transferase. 
C)  Synthase. 
D)  Both carboxylase and synthase. 
E)  All three of these enzymes are used in fatty acid synthesis. 
A)  Carboxylase. 
B)  Transferase. 
C)  Synthase. 
D)  Both carboxylase and synthase. 
E)  All three of these enzymes are used in fatty acid synthesis.

Question 5

Which of the following statements below about the activation of fatty acids is false?

Accepted Answer

A)  Activation involves the formation of a high energy thioester bond. 
B)  Activation is accompanied by hydrolysis of ATP to ADP and Pi. 
C)  Activation includes the formation of an acyl-adenylate intermediate. 
D)  Activation includes hydrolysis of ATP to produce AMP and PPi, with the further hydrolysis of PPi to drive the reaction to completion. 
A)  Activation involves the formation of a high energy thioester bond. 
B)  Activation is accompanied by hydrolysis of ATP to ADP and Pi. 
C)  Activation includes the formation of an acyl-adenylate intermediate. 
D)  Activation includes hydrolysis of ATP to produce AMP and PPi, with the further hydrolysis of PPi to drive the reaction to completion.

Question 6

Which of the following are involved in the development of atherosclerosis?

Accepted Answer

A)  Excess LDL 
B)  Inflammation 
C)  Adhesion molecules 
D)  Monocytes 
E)  none of these 
F) all of these 
A)  Excess LDL 
B)  Inflammation 
C)  Adhesion molecules 
D)  Monocytes 
E)  none of these 
F) all of these

Question 7

Other than their use in nucleic acid synthesis, which energy source is used uniquely for the synthesis of lipids?

Accepted Answer

A)  ATP 
B)  CTP 
C)  GTP 
D)  UTP 
E)  None of these is unique to fatty acid synthesis. 
A)  ATP 
B)  CTP 
C)  GTP 
D)  UTP 
E)  None of these is unique to fatty acid synthesis.

Question 8

Which of the following vitamins and cofactors is not used in β-oxidation?

Accepted Answer

A)  Biotin 
B)  Niacin 
C)  Pantothenic acid 
D)  Riboflavin 
E)  All of these are important in the β-oxidation of fatty acids. 
A)  Biotin 
B)  Niacin 
C)  Pantothenic acid 
D)  Riboflavin 
E)  All of these are important in the β-oxidation of fatty acids.

Question 9

Which of the following reactions is catalyzed by carnitine acyltransferase?

Accepted Answer

A)  carnitine + acyl-CoA --> CoASH + acylcarnitine 
B)  CoASH + acylcarnitine --> carnitine + acyl-CoA 
C)  both of these 
D)  none of these 
A)  carnitine + acyl-CoA --> CoASH + acylcarnitine 
B)  CoASH + acylcarnitine --> carnitine + acyl-CoA 
C)  both of these 
D)  none of these

Question 10

Palmitic acid, with 16 carbons, requires 8 cycles of β-oxidation to produce 8 acetyl-CoA.

Accepted Answer

A) True 
 B)False

Question 11

The β-oxidation of fatty acids with an odd number of carbons requires additional enzymes to allow all the products to enter the citric acid cycle .

Accepted Answer

A) True 
 B)False

Question 12

Which of the following reactants is involved in both fatty acids synthesis and breakdown?

Accepted Answer

A)  CO2. 
B)  Malonyl-CoA 
C)  NADPH. 
D)  Pantothenic acid. 
E)  All of these reactants are involved in both fatty acid synthesis and breakdown. 
A)  CO2. 
B)  Malonyl-CoA 
C)  NADPH. 
D)  Pantothenic acid. 
E)  All of these reactants are involved in both fatty acid synthesis and breakdown.

Question 13

Biosynthesis of compound lipids typically takes place

Accepted Answer

A)  in the mitochondrial matrix 
B)  in the cytosol 
C)  on the endoplasmic reticulum 
D)  in the Golgi apparatus 
E)  none of these 
A)  in the mitochondrial matrix 
B)  in the cytosol 
C)  on the endoplasmic reticulum 
D)  in the Golgi apparatus 
E)  none of these

Question 14

Which of the following is NOT a short term regulator of appetite?

Accepted Answer

A)  ghrelin 
B)  Cholecystokinin 
C)  leptin 
D)  all of these are short term regulators 
A)  ghrelin 
B)  Cholecystokinin 
C)  leptin 
D)  all of these are short term regulators

Question 15

Lipoproteins are incorporated into the cell by a process called pinocytosis.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following is not a function of cholesterol in the human body?

Accepted Answer

A)  Precursor of steroid hormones. 
B)  Energy storage compound. 
C)  Precursor of bile salts. 
D)  Component of cell membranes. 
E)  All of these are important function of cholesterol in humans. 
A)  Precursor of steroid hormones. 
B)  Energy storage compound. 
C)  Precursor of bile salts. 
D)  Component of cell membranes. 
E)  All of these are important function of cholesterol in humans.

Question 17

Which of the following is not an advantage of fatty acids as a form of energy storage?

Accepted Answer

A)  Fatty acids contain more highly reduced carbons than carbohydrates. 
B)  Their hydrophobic nature allows close packing in adipose tissue. 
C)  Storage of fats in muscle tissue makes it readily available for use during activity. 
D)  Fats contain more energy per gram than sugars. 
E)  They do not require water for storage. 
A)  Fatty acids contain more highly reduced carbons than carbohydrates. 
B)  Their hydrophobic nature allows close packing in adipose tissue. 
C)  Storage of fats in muscle tissue makes it readily available for use during activity. 
D)  Fats contain more energy per gram than sugars. 
E)  They do not require water for storage.

Question 18

Approximately how many ATP molecules are netted from the complete oxidation of stearic acid (C−18)?

Accepted Answer

A)  2 
B)  4 
C)  32 
D)  88 
E)  120 
A)  2 
B)  4 
C)  32 
D)  88 
E)  120

Question 19

Synthesis of fatty acids involves simple reversal of the β-oxidation cycle.

Accepted Answer

A) True 
 B)False

Question 20

Scientists think ACC2 may be a target to fight obesity because

Accepted Answer

A)  Inhibiting ACC2 leads to lowered levels of malonyl-CoA 
B)  mice lacking ACC2 are leaner than wild-type mice 
C)  reducing malonyl-CoA relieves the inhibition of CPT-I 
D)  all of these 
A)  Inhibiting ACC2 leads to lowered levels of malonyl-CoA 
B)  mice lacking ACC2 are leaner than wild-type mice 
C)  reducing malonyl-CoA relieves the inhibition of CPT-I 
D)  all of these

Exam 21: Lipid Metabolism

The first true steroid synthesized in the steroid pathway is the following:

The oxidation of an unsaturated fatty acid leads to the production of fewer ATPs than a saturated fatty acid with the same number of carbons because ____

A key intermediate in the catabolism of fatty acids with uneven numbers of carbon atoms is

Which of the following enzyme types is involved in both fatty acid synthesis and breakdown?

Which of the following statements below about the activation of fatty acids is false?

Which of the following are involved in the development of atherosclerosis?

Other than their use in nucleic acid synthesis, which energy source is used uniquely for the synthesis of lipids?

Which of the following vitamins and cofactors is not used in β-oxidation?

Which of the following reactions is catalyzed by carnitine acyltransferase?

Palmitic acid, with 16 carbons, requires 8 cycles of β-oxidation to produce 8 acetyl-CoA.

The β-oxidation of fatty acids with an odd number of carbons requires additional enzymes to allow all the products to enter the citric acid cycle .

Which of the following reactants is involved in both fatty acids synthesis and breakdown?

Biosynthesis of compound lipids typically takes place

Which of the following is NOT a short term regulator of appetite?

Lipoproteins are incorporated into the cell by a process called pinocytosis.

Which of the following is not a function of cholesterol in the human body?

Which of the following is not an advantage of fatty acids as a form of energy storage?

Approximately how many ATP molecules are netted from the complete oxidation of stearic acid (C−18)?

Synthesis of fatty acids involves simple reversal of the β-oxidation cycle.

Scientists think ACC2 may be a target to fight obesity because

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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