Question 1

Why are triacylglycerols an excellent design for energy stores?

Accepted Answer

A)  They are anhydrous. 
B)  They are small. 
C)  They are highly reduced. 
D)  They are anhydrous, and they are small. 
E)  They are anhydrous, and they are highly reduced. 
A)  They are anhydrous. 
B)  They are small. 
C)  They are highly reduced. 
D)  They are anhydrous, and they are small. 
E)  They are anhydrous, and they are highly reduced. E

Question 2

The first step of $\beta$ oxidation is a(n) _________-linked oxidation of the fatty acyl chain.

Accepted Answer

flavin

Question 3

How are unsaturated fatty acids degraded?

Accepted Answer

An unsaturated fatty acid must be converted into a form that can enter the $\beta$-oxidation pathway. For example, in odd-numbered double bonds, the double bond must be converted from one set of carbons to another, which can then be hydrated and oxidized. This requires an isomerase that converts the cis-Δ³ double bond to a trans-Δ² double bond. Even-numbered double bonds are converted via reductase and isomerase reactions. See text Figures 22.11 and 22.12 for further detail.

Question 4

The coenzyme that supplies the reductive power for fatty acid synthesis is ______________.

Accepted Answer

The answer of The coenzyme that supplies the reductive power...

Question 5

How is pyrophosphate formation an important theme in biochemistry?

Accepted Answer

The hydrolysis of inorganic pyrophosphat

Question 6

The synthesis of fatty acids takes place in the _____________ of the cell.

Accepted Answer

The answer of The synthesis of fatty acids takes place...

Question 7

What pathway degrades an acyl-CoA into acetyl CoA?

Accepted Answer

A)  acyl transferase cycle 
B)  chylomicron cycle 
C)  glyoxylate cycle 
D)  carnitine cycle 
E)  $\beta$ oxidation 
A)  acyl transferase cycle 
B)  chylomicron cycle 
C)  glyoxylate cycle 
D)  carnitine cycle 
E)  $\beta$ oxidation

Question 8

What is the fate of glycerol released during lipolysis?

Accepted Answer

The glycerol is absorbed by th

Question 9

Why is the anhydrous nature of triacylglycerols important in energy efficiency?

Accepted Answer

Carbohydrates need to be hydrated to be

Question 10

How many rounds of $\beta$ oxidation would be required for a 16-C fatty acyl chain to be degraded completely to acetyl-CoA?

Accepted Answer

A)  7 
B)  8 
C)  15 
D)  16 
E)  None of the answers is correct. 
A)  7 
B)  8 
C)  15 
D)  16 
E)  None of the answers is correct.

Question 11

What types of reactions do cobalamin enzymes catalyze?

Accepted Answer

A)  intramolecular rearrangements 
B)  methylations 
C)  reduction of ribonucleotides to deoxyribonucleotides 
D)  intramolecular rearrangements and reduction of ribonucleotides to deoxyribonucleotides 
E)  All the answers are correct. 
A)  intramolecular rearrangements 
B)  methylations 
C)  reduction of ribonucleotides to deoxyribonucleotides 
D)  intramolecular rearrangements and reduction of ribonucleotides to deoxyribonucleotides 
E)  All the answers are correct.

Question 12

Which lipoprotein particle transports triacylglycerols from the intestine?

Accepted Answer

A)  chylomicron 
B)  very low density lipoprotein 
C)  intermediate density lipoprotein 
D)  low density lipoprotein 
E)  high density lipoprotein 
A)  chylomicron 
B)  very low density lipoprotein 
C)  intermediate density lipoprotein 
D)  low density lipoprotein 
E)  high density lipoprotein

Question 13

What molecule is used to transport acetyl groups from the matrix to the cytoplasm?

Accepted Answer

A)  acetyl-carnitine 
B)  succinyl CoA 
C)  oxaloacetate 
D)  $\alpha$-ketoglutarate 
E)  citrate 
A)  acetyl-carnitine 
B)  succinyl CoA 
C)  oxaloacetate 
D)  $\alpha$-ketoglutarate 
E)  citrate

Question 14

What cholesterol derivatives facilitate the digestion of fats by incorporating dietary triacylglycerols into micelles in the intestine?

Accepted Answer

A)  vitamin D 
B)  testosterone 
C)  bile acids 
D)  aldosterone 
E)  None of the answers is correct. 
A)  vitamin D 
B)  testosterone 
C)  bile acids 
D)  aldosterone 
E)  None of the answers is correct.

Question 15

Describe the processes that dietary triacylglycerols must go through to be absorbed by intestines and transported in the blood stream.

Accepted Answer

The triacylglycerols must be digested pr

Question 16

Explain this statement: "Fats burn in the flame of carbohydrates."

Accepted Answer

Acetyl CoA formed from fatty acids canno

Question 17

The function of the enzyme acyl CoA synthetase is

Accepted Answer

A)  lipolysis to release free glyceraldehyde. 
B)  ATP-dependent reduction prior to activation. 
C)  ATP-dependent activation of fatty acids using CoA. 
D)  Production of acetyl CoA for the TCA cycle 
E)  None of the answers is correct. 
A)  lipolysis to release free glyceraldehyde. 
B)  ATP-dependent reduction prior to activation. 
C)  ATP-dependent activation of fatty acids using CoA. 
D)  Production of acetyl CoA for the TCA cycle 
E)  None of the answers is correct.

Question 18

How does fatty acid oxidation differ in peroxisomes?

Accepted Answer

A)  The final product is not acetyl CoA but is succinyl CoA. 
B)  NAD+ does not participate in the pathway. 
C)  The initial dehydrogenation reaction is different in that electrons are transferred to O2 to yield H2O2. 
D)  All oxidations use NAD+ as the oxidizing agent. 
E)  None of the answers is correct. 
A)  The final product is not acetyl CoA but is succinyl CoA. 
B)  NAD+ does not participate in the pathway. 
C)  The initial dehydrogenation reaction is different in that electrons are transferred to O2 to yield H2O2. 
D)  All oxidations use NAD+ as the oxidizing agent. 
E)  None of the answers is correct.

Question 19

Which of the following is an example of a short-lived, local-acting hormone?

Accepted Answer

A)  prostaglandin 
B)  testosterone 
C)  estradiol 
D)  insulin 
E)  glucagon 
A)  prostaglandin 
B)  testosterone 
C)  estradiol 
D)  insulin 
E)  glucagon

Question 20

How is acetyl CoA carboxylase regulated globally?

Accepted Answer

A)  By formation of inactive fibers 
B)  By the enzyme being switched off by phosphorylation and activated by dephosphorylation 
C)  By zymogen activation 
D)  By the binding of cAMP 
E)  None of the answers is correct. 
A)  By formation of inactive fibers 
B)  By the enzyme being switched off by phosphorylation and activated by dephosphorylation 
C)  By zymogen activation 
D)  By the binding of cAMP 
E)  None of the answers is correct.

Exam 22: Fatty Acid Metabolism

Why are triacylglycerols an excellent design for energy stores?

The first step of β\betaβ oxidation is a(n) _________-linked oxidation of the fatty acyl chain.

How are unsaturated fatty acids degraded?

The coenzyme that supplies the reductive power for fatty acid synthesis is ______________.

How is pyrophosphate formation an important theme in biochemistry?

The synthesis of fatty acids takes place in the _____________ of the cell.

What pathway degrades an acyl-CoA into acetyl CoA?

What is the fate of glycerol released during lipolysis?

Why is the anhydrous nature of triacylglycerols important in energy efficiency?

How many rounds of β\betaβ oxidation would be required for a 16-C fatty acyl chain to be degraded completely to acetyl-CoA?

What types of reactions do cobalamin enzymes catalyze?

Which lipoprotein particle transports triacylglycerols from the intestine?

What molecule is used to transport acetyl groups from the matrix to the cytoplasm?

What cholesterol derivatives facilitate the digestion of fats by incorporating dietary triacylglycerols into micelles in the intestine?

Describe the processes that dietary triacylglycerols must go through to be absorbed by intestines and transported in the blood stream.

Explain this statement: "Fats burn in the flame of carbohydrates."

The function of the enzyme acyl CoA synthetase is

How does fatty acid oxidation differ in peroxisomes?

Which of the following is an example of a short-lived, local-acting hormone?

How is acetyl CoA carboxylase regulated globally?

Biochemistry: an Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, Repair, and Recombination

Rna Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

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The first step of $\beta$ oxidation is a(n) _________-linked oxidation of the fatty acyl chain.

How many rounds of $\beta$ oxidation would be required for a 16-C fatty acyl chain to be degraded completely to acetyl-CoA?