Question 1

Name the steps involved in converting glycerol into triacylglycerol.

Accepted Answer

(1) Glycerol is first phosphorylated to

Question 2

Which of the following causes inhibition of fatty acid synthesis?

Accepted Answer

A)  increased insulin 
B)  increased AMP-activated protein kinase (AMPK) 
C)  decreased cytoplasmic acyl-CoA 
D)  increased cytoplasmic acetyl-CoA 
A)  increased insulin 
B)  increased AMP-activated protein kinase (AMPK) 
C)  decreased cytoplasmic acyl-CoA 
D)  increased cytoplasmic acetyl-CoA

Question 3

What is the cellular location of the fatty acid oxidation pathway?

Accepted Answer

A)  cytoplasm 
B)  peroxisome 
C)  mitochondrial matrix 
D)  smooth endoplasmic reticulum 
A)  cytoplasm 
B)  peroxisome 
C)  mitochondrial matrix 
D)  smooth endoplasmic reticulum

Question 4

List the five classes of lipoproteins and briefly state the body origin of each.

Accepted Answer

(1) Chylomicrons, which originate from t

Question 5

Which of the following are ketone bodies?

Accepted Answer

A)  "acetyl-CoA, hydroxymethylglutaryl-CoA" 
B)  "$\beta$-ketoacyl-ACP, hydroxymethylglutaryl-CoA" 
C)  "methylmalonyl-CoA, acetyl-CoA" 
D)  "hydroxybutyrate, acetoacetate" 
A)  "acetyl-CoA, hydroxymethylglutaryl-CoA" 
B)  "$\beta$-ketoacyl-ACP, hydroxymethylglutaryl-CoA" 
C)  "methylmalonyl-CoA, acetyl-CoA" 
D)  "hydroxybutyrate, acetoacetate"

Question 6

How many ATPs are obtained from the complete $\beta$-oxidation of one mole of stearoyl-CoA (18Cs) compared with three molecules of glucose (3 * 6C = 18Cs)?

Accepted Answer

A)  106 versus 32 
B)  100 versus 100 
C)  36 versus 90 
D)  120 versus 90 
A)  106 versus 32 
B)  100 versus 100 
C)  36 versus 90 
D)  120 versus 90

Question 7

The uptake of LDLs by cells is triggered by the

Accepted Answer

A)  absorption of the LDL triacylglycerol and phospholipid core. 
B)  hydrolysis of LDL phospholipids by phospholipase enzymes. 
C)  binding of the apoB-100 lipoprotein on LDL to the LDL receptor. 
D)  formation of cholesterol plaques. 
A)  absorption of the LDL triacylglycerol and phospholipid core. 
B)  hydrolysis of LDL phospholipids by phospholipase enzymes. 
C)  binding of the apoB-100 lipoprotein on LDL to the LDL receptor. 
D)  formation of cholesterol plaques.

Question 8

The complete $\beta$-oxidation of 1 mole of palmitic acid (16:0) yields moles of ATP after TCA cycle and oxidative phosphorylation processes.

Accepted Answer

A)  8 
B)  32 
C)  106 
D)  156 
A)  8 
B)  32 
C)  106 
D)  156

Question 9

In triacylglycerol synthesis, from where is the glycerol backbone derived?

Accepted Answer

A)  fatty acyl-CoA 
B)  pyruvate 
C)  dihydroxyacetone phosphate 
D)  acetyl-CoA 
A)  fatty acyl-CoA 
B)  pyruvate 
C)  dihydroxyacetone phosphate 
D)  acetyl-CoA

Question 10

The final formation of cholesterol from squalene involves

Accepted Answer

A)  condensation with HMG-CoA and mevalonate. 
B)  more than 19 reactions including cyclization and oxidation. 
C)  oxidation and the addition of acyl-CoA. 
D)  dimerization and oxidation of squalene. 
A)  condensation with HMG-CoA and mevalonate. 
B)  more than 19 reactions including cyclization and oxidation. 
C)  oxidation and the addition of acyl-CoA. 
D)  dimerization and oxidation of squalene.

Question 11

Describe the roles of the citrate shuttle with regards to the fat synthesis pathway.

Accepted Answer

The citrate shuttle moves acetyl-CoA fro

Question 12

Which of the following stimulate fatty acid synthesis when their concentrations are high?

Accepted Answer

A)  citrate and insulin 
B)  glucagon and citrate 
C)  insulin and acyl-CoA 
D)  citrate, insulin, and palmitoyl-CoA 
A)  citrate and insulin 
B)  glucagon and citrate 
C)  insulin and acyl-CoA 
D)  citrate, insulin, and palmitoyl-CoA

Question 13

The same four reactions that are central to the $\beta$oxidation pathway are also present in the fatty acid synthesis pathway, except they are reversed. What is a key difference between the four reactions in these two pathways?

Accepted Answer

A)  One set of reactions synthesizes an ATP, whereas the other set uses an ATP. 
B)  One set occurs in the muscle, whereas the second pathway occurs in the liver. 
C)  One pathway adds three carbon atoms at a time, whereas the other removes two carbons. 
D)  Four enzymes are used in one, whereas one enzyme is used in the other. 
A)  One set of reactions synthesizes an ATP, whereas the other set uses an ATP. 
B)  One set occurs in the muscle, whereas the second pathway occurs in the liver. 
C)  One pathway adds three carbon atoms at a time, whereas the other removes two carbons. 
D)  Four enzymes are used in one, whereas one enzyme is used in the other.

Question 14

Which of the following is NOT an intermediate in the $\beta$-oxidation of a fatty acid?

Accepted Answer

A)   
B)   
C)   
D)   
A)   
B)   
C)   
D)

Question 15

Carnitine is

Accepted Answer

A)  used for transporting fatty acids into the cell. 
B)  attached to the growing fatty acid chain in fatty acid synthesis. 
C)  attached to fatty acid groups that are moved into the mitochondria for degradation. 
D)  attached to acetyl groups to activate them for addition to the growing fatty acid chain in fatty acid synthesis. 
A)  used for transporting fatty acids into the cell. 
B)  attached to the growing fatty acid chain in fatty acid synthesis. 
C)  attached to fatty acid groups that are moved into the mitochondria for degradation. 
D)  attached to acetyl groups to activate them for addition to the growing fatty acid chain in fatty acid synthesis.

Question 16

How are double bonds added to fatty acid chains in humans?

Accepted Answer

A)  The smooth endoplasmic reticulum is involved in elongating and unsaturating fatty acids. 
B)  FAD is used as an oxidant to create the double bonds in the smooth endoplasmic reticulum. 
C)  Unsaturated fatty acids are not made by humans and are therefore essential fats. 
D)  Fatty acid desaturase enzymes use O2 and NADH to add double bonds to fatty acids. 
A)  The smooth endoplasmic reticulum is involved in elongating and unsaturating fatty acids. 
B)  FAD is used as an oxidant to create the double bonds in the smooth endoplasmic reticulum. 
C)  Unsaturated fatty acids are not made by humans and are therefore essential fats. 
D)  Fatty acid desaturase enzymes use O2 and NADH to add double bonds to fatty acids.

Question 17

Which molecule is used to transport fatty-acyl groups into the mitochondria?

Accepted Answer

A)  CoA-SH 
B)  ATP 
C)  biotin 
D)  carnitine 
A)  CoA-SH 
B)  ATP 
C)  biotin 
D)  carnitine

Question 18

Ketone bodies are

Accepted Answer

A)  transported to the liver for degradation. 
B)  an alternate storage form of glucose. 
C)  used as a fuel source by muscle cells as well as brain cells. 
D)  polymerized to form fatty acids. 
A)  transported to the liver for degradation. 
B)  an alternate storage form of glucose. 
C)  used as a fuel source by muscle cells as well as brain cells. 
D)  polymerized to form fatty acids.

Question 19

Which cofactor is utilized in the following fatty acid oxidation reaction?

Accepted Answer

A)  ATP 
B)  NAD+ 
C)  FAD 
D)  NADP+ 
A)  ATP 
B)  NAD+ 
C)  FAD 
D)  NADP+

Question 20

What precursors are required for the breakdown of palmitate?

Accepted Answer

A)  14 ATP and 14 NADH 
B)  ATP and CoA 
C)  acetyl-CoA 
D)  NADH and FADH2 
A)  14 ATP and 14 NADH 
B)  ATP and CoA 
C)  acetyl-CoA 
D)  NADH and FADH2

Exam 16: Lipid Metabolism

Name the steps involved in converting glycerol into triacylglycerol.

Which of the following causes inhibition of fatty acid synthesis?

What is the cellular location of the fatty acid oxidation pathway?

List the five classes of lipoproteins and briefly state the body origin of each.

Which of the following are ketone bodies?

How many ATPs are obtained from the complete β\betaβ -oxidation of one mole of stearoyl-CoA (18Cs) compared with three molecules of glucose (3 * 6C = 18Cs)?

The uptake of LDLs by cells is triggered by the

The complete β\betaβ -oxidation of 1 mole of palmitic acid (16:0) yields moles of ATP after TCA cycle and oxidative phosphorylation processes.

In triacylglycerol synthesis, from where is the glycerol backbone derived?

The final formation of cholesterol from squalene involves

Describe the roles of the citrate shuttle with regards to the fat synthesis pathway.

Which of the following stimulate fatty acid synthesis when their concentrations are high?

The same four reactions that are central to the β\betaβ oxidation pathway are also present in the fatty acid synthesis pathway, except they are reversed. What is a key difference between the four reactions in these two pathways?

Which of the following is NOT an intermediate in the β\betaβ -oxidation of a fatty acid?

Carnitine is

How are double bonds added to fatty acid chains in humans?

Which molecule is used to transport fatty-acyl groups into the mitochondria?

Ketone bodies are

Which cofactor is utilized in the following fatty acid oxidation reaction?

What precursors are required for the breakdown of palmitate?

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

Filters

How many ATPs are obtained from the complete $\beta$ -oxidation of one mole of stearoyl-CoA (18Cs) compared with three molecules of glucose (3 * 6C = 18Cs)?

The complete $\beta$ -oxidation of 1 mole of palmitic acid (16:0) yields moles of ATP after TCA cycle and oxidative phosphorylation processes.

The same four reactions that are central to the $\beta$ oxidation pathway are also present in the fatty acid synthesis pathway, except they are reversed. What is a key difference between the four reactions in these two pathways?

Which of the following is NOT an intermediate in the $\beta$ -oxidation of a fatty acid?