Question 1

Which of the following mechanisms explains why fatty acid synthesis and breakdown do not compete with each other in the body?

Accepted Answer

A)  Synthesis and breakdown take place in two separate compartments of the cell. 
B)  One process uses NADH\NAD+ and the other uses NADPH\NADP+. 
C)  They are not attached to the same carrier molecule in the two processes. 
D)  All of these mechanisms are in operation. 
E)  None of these 
A)  Synthesis and breakdown take place in two separate compartments of the cell. 
B)  One process uses NADH\NAD+ and the other uses NADPH\NADP+. 
C)  They are not attached to the same carrier molecule in the two processes. 
D)  All of these mechanisms are in operation. 
E)  None of these D

Question 2

"Ketone bodies" are formed when

Accepted Answer

A)  oxaloacetate is converted to acetoacetyl-CoA. 
B)  there is a deficiency of acetyl-CoA. 
C)  there is not enough oxaloacetate to react with available acetyl-CoA. 
D)  an organism consumes excessive amounts of carbohydrate compared to its lipid intake. 
E)  none of these 
A)  oxaloacetate is converted to acetoacetyl-CoA. 
B)  there is a deficiency of acetyl-CoA. 
C)  there is not enough oxaloacetate to react with available acetyl-CoA. 
D)  an organism consumes excessive amounts of carbohydrate compared to its lipid intake. 
E)  none of these C

Question 3

Which of the following is not true regarding ketone bodies?

Accepted Answer

A)  Ketone bodies form during the catabolism of fats. 
B)  Ketone bodies are an effective means for weight loss, since the body will excrete them in the urine. 
C)  The first enzyme used in the production of ketone bodies is thiolase 
D)  Ketone bodies are always an alternative fuel in all tissues 
A)  Ketone bodies form during the catabolism of fats. 
B)  Ketone bodies are an effective means for weight loss, since the body will excrete them in the urine. 
C)  The first enzyme used in the production of ketone bodies is thiolase 
D)  Ketone bodies are always an alternative fuel in all tissues D

Question 4

Compared to β -oxidation, fatty acid synthesis requires this extra vitamin or cofactor.

Accepted Answer

A)  Biotin 
B)  Riboflavin 
C)  Niacin 
D)  Pantothenic acid 
E)  All of these are used in both pathways. 
A)  Biotin 
B)  Riboflavin 
C)  Niacin 
D)  Pantothenic acid 
E)  All of these are used in both pathways.

Question 5

Phospholipases are designated A, B, etc , based on

Accepted Answer

A)  the different sites in the molecule where they cleave the phospholipids. 
B)  whether they are phosphorylases or hydrolases. 
C)  whether they use NAD as a cofactor. 
D)  whether they use ATP as a cofactor. 
A)  the different sites in the molecule where they cleave the phospholipids. 
B)  whether they are phosphorylases or hydrolases. 
C)  whether they use NAD as a cofactor. 
D)  whether they use ATP as a cofactor.

Question 6

Fatty acid catabolism is called β -oxidation, since the second or β carbon from the carboxyl group is the site of oxidation.

Accepted Answer

A) True 
 B)False

Question 7

When an acyl group is being transferred from the cytosol to the mitochondria for oxidation, the order of the enzymes it encounters is:

Accepted Answer

A)  CPT-I: Carnitine Translocase: CPT-II 
B)  Carnitine Translocase: CPT-I: CPT-II 
C)  CPT-II: Carnitine Translocase: CPT-I 
D)  none of these 
A)  CPT-I: Carnitine Translocase: CPT-II 
B)  Carnitine Translocase: CPT-I: CPT-II 
C)  CPT-II: Carnitine Translocase: CPT-I 
D)  none of these

Question 8

Since acetyl-CoA carboxylase is key to the synthesis of fatty acids, inhibitors of this enzyme may be useful for weight loss or treatment of obesity.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following best describes carnitine?

Accepted Answer

A)  It transports fatty acids across the inner mitochondrial membrane for breakdown. 
B)  It transports acetyl-CoA to the cytosol for fatty acid synthesis. 
C)  It's a precursor of cholesterol. 
D)  It carries growing acyl chains during fatty acid synthesis. 
E)  none of these 
A)  It transports fatty acids across the inner mitochondrial membrane for breakdown. 
B)  It transports acetyl-CoA to the cytosol for fatty acid synthesis. 
C)  It's a precursor of cholesterol. 
D)  It carries growing acyl chains during fatty acid synthesis. 
E)  none of these

Question 10

Reduction reactions during fatty acid synthesis utilize

Accepted Answer

A)  FADH2. 
B)  NADH. 
C)  NADPH. 
D)  FADH2 and NADH. 
E)  FADH2 and NADPH. 
A)  FADH2. 
B)  NADH. 
C)  NADPH. 
D)  FADH2 and NADH. 
E)  FADH2 and NADPH.

Question 11

Which of the following is true concerning phospholipases?

Accepted Answer

A)  Many snake venoms contain phospholipases 
B)  Phospholipase D is a component in some spider venoms 
C)  Phospholipases in snake venoms can lead to the lysing of blood cells 
D)  All of these 
A)  Many snake venoms contain phospholipases 
B)  Phospholipase D is a component in some spider venoms 
C)  Phospholipases in snake venoms can lead to the lysing of blood cells 
D)  All of these

Question 12

Which of the following is not associated with coronary heart disease?

Accepted Answer

A)  high relative levels of HDLs 
B)  high levels of LDLs 
C)  absence or dysfunction of LDL receptors 
D)  serum cholesterol levels of 300 mg\dl or higher 
A)  high relative levels of HDLs 
B)  high levels of LDLs 
C)  absence or dysfunction of LDL receptors 
D)  serum cholesterol levels of 300 mg\dl or higher

Question 13

Of the processes listed below, which is not an important source of acetyl-CoA?

Accepted Answer

A)  pentose phosphate pathway 
B)  amino acid degradation 
C)  glycolysis 
D)  fatty acid oxidation 
A)  pentose phosphate pathway 
B)  amino acid degradation 
C)  glycolysis 
D)  fatty acid oxidation

Question 14

The first three reactions of the β -oxidation cycle of fatty acids produce

Accepted Answer

A)  two moles of NADH 
B)  two moles of FADH2 
C)  one mole each of NADH and FADH2 
D)  two moles of ATP 
A)  two moles of NADH 
B)  two moles of FADH2 
C)  one mole each of NADH and FADH2 
D)  two moles of ATP

Question 15

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 16

Lipids yield more ATP than sugars because

Accepted Answer

A)  they have more carbon atoms than sugars. 
B)  their carbon atoms are more highly reduced. 
C)  both of these 
D)  neither of these 
A)  they have more carbon atoms than sugars. 
B)  their carbon atoms are more highly reduced. 
C)  both of these 
D)  neither of these

Question 17

The bond linking a fatty acid to coenzyme A is

Accepted Answer

A)  an ester. 
B)  a thioester. 
C)  an anhydride. 
D)  an ether. 
E)  none of these 
A)  an ester. 
B)  a thioester. 
C)  an anhydride. 
D)  an ether. 
E)  none of these

Question 18

The ultimate precursor of all the carbon atoms in steroids is

Accepted Answer

A)  acetyl-CoA (acetyl group) 
B)  oxaloacetate 
C)  succinyl-CoA (succinyl group) 
D)  α -ketoglutarate 
A)  acetyl-CoA (acetyl group) 
B)  oxaloacetate 
C)  succinyl-CoA (succinyl group) 
D)  α -ketoglutarate

Question 19

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 20

The acyl carrier used in fatty acid synthesis is similar to coenzyme A.

Accepted Answer

A) True 
 B)False

Exam 21: Lipid Metabolism

Which of the following mechanisms explains why fatty acid synthesis and breakdown do not compete with each other in the body?

"Ketone bodies" are formed when

Which of the following is not true regarding ketone bodies?

Compared to β -oxidation, fatty acid synthesis requires this extra vitamin or cofactor.

Phospholipases are designated A, B, etc , based on

Fatty acid catabolism is called β -oxidation, since the second or β carbon from the carboxyl group is the site of oxidation.

When an acyl group is being transferred from the cytosol to the mitochondria for oxidation, the order of the enzymes it encounters is:

Since acetyl-CoA carboxylase is key to the synthesis of fatty acids, inhibitors of this enzyme may be useful for weight loss or treatment of obesity.

Which of the following best describes carnitine?

Reduction reactions during fatty acid synthesis utilize

Which of the following is true concerning phospholipases?

Which of the following is not associated with coronary heart disease?

Of the processes listed below, which is not an important source of acetyl-CoA?

The first three reactions of the β -oxidation cycle of fatty acids produce

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

Lipids yield more ATP than sugars because

The bond linking a fatty acid to coenzyme A is

The ultimate precursor of all the carbon atoms in steroids is

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

The acyl carrier used in fatty acid synthesis is similar to coenzyme A.

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 the 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

Filters