Question 1

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 2

How many NADPH are oxidized in the synthesis of palmitoyl-CoA from eight molecules of acetyl-CoA?

Accepted Answer

A)  1 
B)  7 
C)  8 
D)  14 
E)  16 
A)  1 
B)  7 
C)  8 
D)  14 
E)  16

Question 3

The enzyme activity catalyzing the reaction shown is best termed a

Accepted Answer

A)  reductase 
B)  hydratase 
C)  dehydratase 
D)  dehydrogenase 
A)  reductase 
B)  hydratase 
C)  dehydratase 
D)  dehydrogenase

Question 4

How is acetyl-CoA transported from the mitochondria to the cytosol for fatty acid synthesis?

Accepted Answer

A)  directly as acetyl-CoA 
B)  through a temporary linkage to carnitine 
C)  as citric acid 
D)  There is no reason to transport acetyl-CoA from the mitochondria to the cytosol, since it is produced primarily in the cytosol. 
A)  directly as acetyl-CoA 
B)  through a temporary linkage to carnitine 
C)  as citric acid 
D)  There is no reason to transport acetyl-CoA from the mitochondria to the cytosol, since it is produced primarily in the cytosol.

Question 5

During fatty acid synthesis, the growing fatty acid is always bound to a protein.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following statements concerning β -oxidation of fatty acids is false ?

Accepted Answer

A)  Initiation occurs at the methyl end of the fatty acid. 
B)  β -oxidation is the primary route for degradation of fatty acids. 
C)  β -oxidation takes place in the mitochondrial matrix. 
D)  Two-carbon units are successively eliminated with each round. 
A)  Initiation occurs at the methyl end of the fatty acid. 
B)  β -oxidation is the primary route for degradation of fatty acids. 
C)  β -oxidation takes place in the mitochondrial matrix. 
D)  Two-carbon units are successively eliminated with each round.

Question 7

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 8

Leptin is

Accepted Answer

A)  a peptide hormone 
B)  an appetite supressant 
C)  a hormone that stimulates fat breakdown 
D)  all of these 
A)  a peptide hormone 
B)  an appetite supressant 
C)  a hormone that stimulates fat breakdown 
D)  all of these

Question 9

The β -oxidation of unsaturated fatty acids requires additional enzymes to isomerize the double bonds.

Accepted Answer

A) True 
 B)False

Question 10

The enzyme activity catalyzing the reaction shown is best termed a

Accepted Answer

A)  reductase 
B)  ketothiolase 
C)  transferase 
D)  dehydratase 
A)  reductase 
B)  ketothiolase 
C)  transferase 
D)  dehydratase

Question 11

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 12

If the bicarbonate used in malonyl-CoA synthesis were labeled with 14C in the biosynthesis of palmitate, where would the label be found in the reaction products?

Accepted Answer

A)  CO2 
B)  C − 16 of palmitate 
C)  C − 1 of palmitate 
D)  evenly distributed in palmitate 
A)  CO2 
B)  C − 16 of palmitate 
C)  C − 1 of palmitate 
D)  evenly distributed in palmitate

Question 13

Which of the following is not true regarding catabolism of triacylglycerols?

Accepted Answer

A)  Control of release of fatty acids from triacylglycerols in adipocytes involves cyclic AMP as a second messenger. 
B)  When cAMP is a second messenger in the catabolsim of triacylglycerols, it activates a protein kinase 
C)  The protein kinase, once activated, cleaves fatty acids from the triacylglycerol 
D)  The phosphorylated form of triacylglycerol lipase is the active form 
E)  All of these are true 
A)  Control of release of fatty acids from triacylglycerols in adipocytes involves cyclic AMP as a second messenger. 
B)  When cAMP is a second messenger in the catabolsim of triacylglycerols, it activates a protein kinase 
C)  The protein kinase, once activated, cleaves fatty acids from the triacylglycerol 
D)  The phosphorylated form of triacylglycerol lipase is the active form 
E)  All of these are true

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

The metabolically activated form of a fatty acid is

Accepted Answer

A)  an ester 
B)  a Schiff base 
C)  a phosphate ester 
D)  a thioester 
E)  none of these 
A)  an ester 
B)  a Schiff base 
C)  a phosphate ester 
D)  a thioester 
E)  none of these

Question 16

Isomerization of the double bonds of polyunsaturated fatty acids involves both cis-trans isomerization and changing the position of the double bonds.

Accepted Answer

A) True 
 B)False

Question 17

The carrier molecule which transports fatty acids through the inner mitochondrial membrane is

Accepted Answer

A)  ATP. 
B)  Carnitine. 
C)  Coenzyme A. 
D)  Lipoic Acid. 
E)  none of these 
A)  ATP. 
B)  Carnitine. 
C)  Coenzyme A. 
D)  Lipoic Acid. 
E)  none of these

Question 18

When the blood contains a high concentration of LDLs, the cells respond by making fewer receptors to react with the LDL.

Accepted Answer

A) True 
 B)False

Question 19

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

Question 20

The oxidation of unsaturated fatty acids specifically requires

Accepted Answer

A)  a cis-trans isomerase and a reductase. 
B)  a cis-trans isomerase and a dehydrogenase. 
C)  a dehydrogenase and a reductase. 
D)  a dehydrogenase and a hydrase. 
E)  none of these 
A)  a cis-trans isomerase and a reductase. 
B)  a cis-trans isomerase and a dehydrogenase. 
C)  a dehydrogenase and a reductase. 
D)  a dehydrogenase and a hydrase. 
E)  none of these

Exam 21: Lipid Metabolism

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

How many NADPH are oxidized in the synthesis of palmitoyl-CoA from eight molecules of acetyl-CoA?

The enzyme activity catalyzing the reaction shown is best termed a

How is acetyl-CoA transported from the mitochondria to the cytosol for fatty acid synthesis?

During fatty acid synthesis, the growing fatty acid is always bound to a protein.

Which of the following statements concerning β -oxidation of fatty acids is false ?

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

Leptin is

The β -oxidation of unsaturated fatty acids requires additional enzymes to isomerize the double bonds.

The enzyme activity catalyzing the reaction shown is best termed a

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

If the bicarbonate used in malonyl-CoA synthesis were labeled with 14C in the biosynthesis of palmitate, where would the label be found in the reaction products?

Which of the following is not true regarding catabolism of triacylglycerols?

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

The metabolically activated form of a fatty acid is

Isomerization of the double bonds of polyunsaturated fatty acids involves both cis-trans isomerization and changing the position of the double bonds.

The carrier molecule which transports fatty acids through the inner mitochondrial membrane is

When the blood contains a high concentration of LDLs, the cells respond by making fewer receptors to react with the LDL.

Scientists think ACC2 may be a target to fight obesity because

The oxidation of unsaturated fatty acids specifically requires

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

If the bicarbonate used in malonyl-CoA synthesis were labeled with ¹⁴C in the biosynthesis of palmitate, where would the label be found in the reaction products?