Question 1

Which compound is NOT considered a "ketone body"?

Accepted Answer

A)  acetoacetate 
B)  3-hydroxybutyrate 
C)  acetone 
D)  dihydroxyacetone 
E)  $\beta$-hydroxybutyrate 
A)  acetoacetate 
B)  3-hydroxybutyrate 
C)  acetone 
D)  dihydroxyacetone 
E)  $\beta$-hydroxybutyrate D

Question 2

Which statement(s) about lipases is/are TRUE?
1.  Intestinal lipases break down lipids in micelles found in the small intestine. 
2.  Hormone-sensitive lipase is located primarily in hepatocytes. 
3.  Lipoprotein lipase is activated in capillaries by apoC-II. 
4.  Lipoprotein lipase delivers free fatty acids to peripheral tissues.

Accepted Answer

A) 	1 and 2 
B) 	2 only 
C) 	1 and 4 
D) 	1, 3, and 4 
E) 	4 only 
A) 	1 and 2 
B) 	2 only 
C) 	1 and 4 
D) 	1, 3, and 4 
E) 	4 only D

Question 3

Free fatty acids in the bloodstream are:

Accepted Answer

A)  bound to hemoglobin. 
B)  carried by the protein serum albumin. 
C)  freely soluble in the aqueous phase of the blood. 
D)  nonexistent; the blood does not contain free fatty acids. 
E)  present at levels that are independent of epinephrine. 
A)  bound to hemoglobin. 
B)  carried by the protein serum albumin. 
C)  freely soluble in the aqueous phase of the blood. 
D)  nonexistent; the blood does not contain free fatty acids. 
E)  present at levels that are independent of epinephrine. B

Question 4

In the following equation, which substance is being reduced?

Accepted Answer

A)  $\beta$-ketoacyl-CoA 
B)  l-$\beta$-hydroxy-acyl-CoA 
C)  NADH 
D)  NAD+ 
E)  H+ 
A)  $\beta$-ketoacyl-CoA 
B)  l-$\beta$-hydroxy-acyl-CoA 
C)  NADH 
D)  NAD+ 
E)  H+

Question 5

What are the two major sites in animals for fatty acid catabolism?

Accepted Answer

A)  the liver and the kidneys 
B)  the liver and the brain 
C)  skeletal muscle and the liver 
D)  adipose tissue and the liver 
E)  adipose tissue and skeletal muscle 
A)  the liver and the kidneys 
B)  the liver and the brain 
C)  skeletal muscle and the liver 
D)  adipose tissue and the liver 
E)  adipose tissue and skeletal muscle

Question 6

In the citric acid cycle, a double bond is introduced into a four-carbon compound containing the -CH2-CH2- group, producing fumarate. Show a similar reaction that occurs in the $\beta$-oxidation pathway.

Accepted Answer

In the citric acid cycle, the specific r

Question 7

Which statement is NOT true about vitamin B12?

Accepted Answer

A)  Vitamin B12 contains a porphyrin ring. 
B)  Vitamin B12 contains a carbon-cobalt bond. 
C)  Vitamin B12 readily undergoes homolytic bond cleavage. 
D)  Deficiency of vitamin B12 causes pernicious anemia. 
E)  Vitamin B12 catalyzes hydrogen atom exchange with solvent H2O. 
A)  Vitamin B12 contains a porphyrin ring. 
B)  Vitamin B12 contains a carbon-cobalt bond. 
C)  Vitamin B12 readily undergoes homolytic bond cleavage. 
D)  Deficiency of vitamin B12 causes pernicious anemia. 
E)  Vitamin B12 catalyzes hydrogen atom exchange with solvent H2O.

Question 8

Which statement is FALSE regarding the catabolic oxidation of 1 mol of palmitate?

Accepted Answer

A)  8 mol of acetyl-CoA are formed. 
B)  AMP and 2 Pi are formed in the cytosol. 
C)  The oxidation reactions occur in the mitochondria. 
D)  8 mol of H2O are required. 
E)  Carnitine is required for the transport of fatty acids into the mitochondrial matrix. 
A)  8 mol of acetyl-CoA are formed. 
B)  AMP and 2 Pi are formed in the cytosol. 
C)  The oxidation reactions occur in the mitochondria. 
D)  8 mol of H2O are required. 
E)  Carnitine is required for the transport of fatty acids into the mitochondrial matrix.

Question 9

An experimenter studying the oxidation of fatty acids in extracts of liver found that when palmitate (16:0) was provided as substrate, it was completely oxidized to CO2. However, when undecanoic acid (11:0) was added as substrate, incomplete oxidation occurred unless he bubbled CO2 through the reaction mixture. The addition of the protein avidin, which binds tightly to biotin, prevented the complete oxidation of undecanoic acid even in the presence of CO2, although it had no effect on palmitate oxidation. Explain these observations in light of what you know of fatty acid oxidation reactions.

Accepted Answer

The observations can be explained by the

Question 10

The carbon atoms from a fatty acid with an odd number of carbons will enter the citric acid cycle as acetyl-CoA and:

Accepted Answer

A)  butyrate. 
B)  citrate. 
C)  malate. 
D)  succinyl-CoA. 
E)  $\alpha$-ketoglutarate. 
A)  butyrate. 
B)  citrate. 
C)  malate. 
D)  succinyl-CoA. 
E)  $\alpha$-ketoglutarate.

Question 11

What products from the oxidation of odd-numbered fatty acids enter the citric acid cycle?

Accepted Answer

A)  acetyl-CoA and citrate 
B)  acetyl-CoA and malonyl-CoA 
C)  acetyl-CoA and propionyl-CoA 
D)  acetyl-CoA and succinyl-CoA 
E)  succinyl-CoA and propionyl-CoA 
A)  acetyl-CoA and citrate 
B)  acetyl-CoA and malonyl-CoA 
C)  acetyl-CoA and propionyl-CoA 
D)  acetyl-CoA and succinyl-CoA 
E)  succinyl-CoA and propionyl-CoA

Question 12

Explain why lipases are required in BOTH the intestine and in the bloodstream.

Accepted Answer

Lipases are required in both the intesti

Question 13

Why is it more efficient to store energy as lipid, rather than as glycogen?

Accepted Answer

Lipids, primarily in the form of fats, a

Question 14

In which cellular compartment are ketone bodies synthesized?

Accepted Answer

A)  the cytosol 
B)  the mitochondrial matrix 
C)  the mitochondrial intermembrane space 
D)  the endoplasmic reticulum 
E)  peroxisomes 
A)  the cytosol 
B)  the mitochondrial matrix 
C)  the mitochondrial intermembrane space 
D)  the endoplasmic reticulum 
E)  peroxisomes

Question 15

If you received a laboratory report showing the presence of a high concentration of ketone bodies in the urine of a patient, what disease would you suspect? Why do ketone bodies accumulate in such patients?

Accepted Answer

If a laboratory report indicates a high

Question 16

How much carbon dioxide is produced from the complete aerobic catabolism of one molecule of linoleate via catabolic pathways?

Accepted Answer

A)  18 CO2 
B)  17 CO2 
C)  16 CO2 
D)  15 CO2 
E)  8 CO2 
A)  18 CO2 
B)  17 CO2 
C)  16 CO2 
D)  15 CO2 
E)  8 CO2

Question 17

Which statement is FALSE regarding ketone bodies?

Accepted Answer

A)  During prolonged starvation, the brain adapts to using ketone bodies as a fuel. 
B)  Excess acetone production during ketoacidosis is exhaled through the lungs. 
C)  Ketone bodies can be used as a carbon source for fatty acid synthesis. 
D)  Ketone bodies can be converted to glucose during ketosis. 
E)  Ketone bodies are formed when the glucagon/insulin ratio is high. 
A)  During prolonged starvation, the brain adapts to using ketone bodies as a fuel. 
B)  Excess acetone production during ketoacidosis is exhaled through the lungs. 
C)  Ketone bodies can be used as a carbon source for fatty acid synthesis. 
D)  Ketone bodies can be converted to glucose during ketosis. 
E)  Ketone bodies are formed when the glucagon/insulin ratio is high.

Question 18

In solution at pH 6.5, palmitate has an overall negative charge. This means that the pKa of palmitate is:

Accepted Answer

A)   6.5. 
C)  6.5. 
D)  All of the answers are correct. 
A)   6.5. 
C)  6.5. 
D)  All of the answers are correct.

Question 19

If the fatty acid 16:0 is catabolized completely, to carbon dioxide and water, the net yield of ATP per molecule of fatty acid is _____ ATP.

Accepted Answer

A)  90.5 
B)  97.5 
C)  88.5 
D)  106 
E)  108 
A)  90.5 
B)  97.5 
C)  88.5 
D)  106 
E)  108

Question 20

In the first step of fatty acid oxidation, the fatty acid (R-COOH) is converted to its coenzyme A derivative in the following reaction:
R-COOH + ATP + CoA-SH $\rightarrow$  R-CO-S-CoA + AMP + PPi
The standard free-energy change ($\Delta$G'°) for this reaction is -15 kJ/mol
What will tend to make the reaction even more favorable when it takes place within a cell?

Accepted Answer

The reaction in question is the activati

Exam 17: Fatty Acid Catabolism

Which compound is NOT considered a "ketone body"?

Free fatty acids in the bloodstream are:

In the following equation, which substance is being reduced?

What are the two major sites in animals for fatty acid catabolism?

In the citric acid cycle, a double bond is introduced into a four-carbon compound containing the -CH2-CH2- group, producing fumarate. Show a similar reaction that occurs in the β\betaβ -oxidation pathway.

Which statement is NOT true about vitamin B12?

Which statement is FALSE regarding the catabolic oxidation of 1 mol of palmitate?

The carbon atoms from a fatty acid with an odd number of carbons will enter the citric acid cycle as acetyl-CoA and:

What products from the oxidation of odd-numbered fatty acids enter the citric acid cycle?

Explain why lipases are required in BOTH the intestine and in the bloodstream.

Why is it more efficient to store energy as lipid, rather than as glycogen?

In which cellular compartment are ketone bodies synthesized?

If you received a laboratory report showing the presence of a high concentration of ketone bodies in the urine of a patient, what disease would you suspect? Why do ketone bodies accumulate in such patients?

How much carbon dioxide is produced from the complete aerobic catabolism of one molecule of linoleate via catabolic pathways?

Which statement is FALSE regarding ketone bodies?

In solution at pH 6.5, palmitate has an overall negative charge. This means that the pKa of palmitate is:

If the fatty acid 16:0 is catabolized completely, to carbon dioxide and water, the net yield of ATP per molecule of fatty acid is _____ ATP.

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Principles of Metabolic Regulation

The Citric Acid Cycle

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

In the citric acid cycle, a double bond is introduced into a four-carbon compound containing the -CH₂-CH₂- group, producing fumarate. Show a similar reaction that occurs in the $\beta$ -oxidation pathway.

Which statement is NOT true about vitamin B₁₂?

In solution at pH 6.5, palmitate has an overall negative charge. This means that the pK_a of palmitate is: