Question 1

The first step in vitamin D synthesis is unusual. What is it?

Accepted Answer

The precursor to vitamin D is 7-dehydrocholesterol. It is photolyzed in the skin by UV light to the vitamin D3, also known as cholecalciferol, which is converted via a series of steps to vitamin D.

Question 2

Which of the following is/are major component(s) of low-density lipoproteins?

Accepted Answer

A)  phospholipid 
B)  apoprotein B-100 
C)  cholesteryl ester 
D)  All of the above. 
E)  None of the above. 
A)  phospholipid 
B)  apoprotein B-100 
C)  cholesteryl ester 
D)  All of the above. 
E)  None of the above. D

Question 3

Choose the correct answer from the list below. Not all of the answers will be used.
-_______________: The vitamin that is a derivative of cholesterol.

Accepted Answer

A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin 
A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin G

Question 4

The role of lipoprotein particles is to:

Accepted Answer

A)  solubilize hydrophobic lipids. 
B)  aid in clot formation. 
C)  contain cell-targeting signals. 
D)  A and B. 
E)  A and C. 
A)  solubilize hydrophobic lipids. 
B)  aid in clot formation. 
C)  contain cell-targeting signals. 
D)  A and B. 
E)  A and C.

Question 5

Choose the correct answer from the list below. Not all of the answers will be used.
-_______________ is the process by which LDL enters the cell.

Accepted Answer

A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin 
A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin

Question 6

Which of the following combines with cholic acid to form a major bile salt?

Accepted Answer

A)  ATP 
B)  glycine 
C)  glycerol 
D)  A and B 
E)  A, B, and C 
A)  ATP 
B)  glycine 
C)  glycerol 
D)  A and B 
E)  A, B, and C

Question 7

HMG CoA is synthesized from acetyl CoA and:

Accepted Answer

A)  oxaloacetate. 
B)  acetoacetyl CoA. 
C)  acetyl CoA. 
D)  farnesyl pyrophosphate. 
E)  mevalonate. 
A)  oxaloacetate. 
B)  acetoacetyl CoA. 
C)  acetyl CoA. 
D)  farnesyl pyrophosphate. 
E)  mevalonate.

Question 8

In membrane-lipid biosynthesis, the nucleotide ___________________ is used to activate the components of the reaction.

Accepted Answer

cytidine t

Question 9

The major carrier(s) of dietary fat from the intestine is/are:

Accepted Answer

A)  VLDL. 
B)  chylomicrons. 
C)  HDL. 
D)  LDL. 
E)  IDL. 
A)  VLDL. 
B)  chylomicrons. 
C)  HDL. 
D)  LDL. 
E)  IDL.

Question 10

Feedback regulation of cholesterol synthesis is mainly controlled at the step catalyzed by the enzyme:

Accepted Answer

A)  3-hydroxy-3-methylglutaryl (HMG) CoA reductase. 
B)  geranyl transferase. 
C)  HMG transferase. 
D)  farnesyl reductase. 
E)  None of the above. 
A)  3-hydroxy-3-methylglutaryl (HMG) CoA reductase. 
B)  geranyl transferase. 
C)  HMG transferase. 
D)  farnesyl reductase. 
E)  None of the above.

Question 11

In the biosynthesis of phosphatidates, the fatty acyl group attached to the C-2 position is usually ___________________.

Accepted Answer

The answer of In the biosynthesis of phosphatidates, the fatty...

Question 12

What are the three stages of cholesterol synthesis?

Accepted Answer

The stages are: (1) the synthe

Question 13

How is methionine metabolism related to the synthesis of phosphatidyl choline?

Accepted Answer

One way the phosphatidyl choline can be

Question 14

Choose the correct answer from the list below. Not all of the answers will be used.
-The membrane component _______________ is produced from the activated precursor CDP-diacylglycerol.

Accepted Answer

A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin 
A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin

Question 15

What are some of the medical strategies to control cholesterol levels at an appropriate level?

Accepted Answer

High blood levels of cholesterol are the

Question 16

Choose the correct answer from the list below. Not all of the answers will be used.
-_______________ is a component of the myelin sheath.

Accepted Answer

A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin 
A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin

Question 17

How are gangliosides synthesized?

Accepted Answer

Gangliosides have oligosaccharides attac

Question 18

What is phosphatidyl choline? How is it synthesized in mammals?

Accepted Answer

Phosphatidyl choline is one of the most

Question 19

Choose the correct answer from the list below. Not all of the answers will be used.
-Cholesterol and triacylglycerols are transported in body fluids in the form of _______________.

Accepted Answer

A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin 
A) liver 
B) receptor-mediated endocytosis 
C) phosphatidyl ethanolamine 
D) muscle 
E) lipoprotein particles
F)dihydroxyacetone phosphate
G)vitamin D
H)pregnenolone
I)glycocholate
J)acetyl CoA
K)vitamin A
L)sphingomyelin

Question 20

In the biosynthesis of sphingomyelin, the terminal hydroxyl group of ceramide is substituted with ___________________.

Accepted Answer

The answer of In the biosynthesis of sphingomyelin, the terminal...

Exam 29: Lipid Synthesis

The first step in vitamin D synthesis is unusual. What is it?

Which of the following is/are major component(s) of low-density lipoproteins?

Choose the correct answer from the list below. Not all of the answers will be used. -_______________: The vitamin that is a derivative of cholesterol.

The role of lipoprotein particles is to:

Choose the correct answer from the list below. Not all of the answers will be used. -_______________ is the process by which LDL enters the cell.

Which of the following combines with cholic acid to form a major bile salt?

HMG CoA is synthesized from acetyl CoA and:

In membrane-lipid biosynthesis, the nucleotide ___________________ is used to activate the components of the reaction.

The major carrier(s) of dietary fat from the intestine is/are:

Feedback regulation of cholesterol synthesis is mainly controlled at the step catalyzed by the enzyme:

In the biosynthesis of phosphatidates, the fatty acyl group attached to the C-2 position is usually ___________________.

What are the three stages of cholesterol synthesis?

How is methionine metabolism related to the synthesis of phosphatidyl choline?

Choose the correct answer from the list below. Not all of the answers will be used. -The membrane component _______________ is produced from the activated precursor CDP-diacylglycerol.

What are some of the medical strategies to control cholesterol levels at an appropriate level?

Choose the correct answer from the list below. Not all of the answers will be used. -_______________ is a component of the myelin sheath.

How are gangliosides synthesized?

What is phosphatidyl choline? How is it synthesized in mammals?

Choose the correct answer from the list below. Not all of the answers will be used. -Cholesterol and triacylglycerols are transported in body fluids in the form of _______________.

In the biosynthesis of sphingomyelin, the terminal hydroxyl group of ceramide is substituted with ___________________.

Biochemistry and the Unity of Life

Water, Weak Bonds, and the Generation of Order Out of Chaos

Amino Acids

Protein Three-Dimensional Structure

Techniques in Protein Biochemistry

Basic Concepts of Enzyme Action

Kinetics and Regulation

Mechanisms and Inhibitors

Hemoglobin: an Allosteric Protein

Carbohydrates

Lipids

Membrane Structure and Function

Signal Transduction Pathways

Digestion: Turning a Meal Into Cellular Biochemicals

Metabolism: Basic Concepts and Design

Glycolysis

Gluconeogenesis

Preparation for the Cycle

Harvesting Electrons From the Cycle

The Electron Transport Chain

The Proton-Motive Force

The Light Reactions

The Calvin Cycle

Glycogen Degradation

Glycogen Synthesis

The Pentose Phosphate Pathway

Fatty Acid Degredation

Fatty Acid Synthesis

Amino Acid Degradation and the Urea Cycle

Amino Acids Synthesis

Nucleotide Metabolism

The Structure of Informational Macromolecules: Dna and Rna

DNA Replication

DNA Repair and Recombination

RNA Synthesis and Regulation in Prokaryotes

Gene Expression in Eukaryotes

RNA Processing in Eukaryotes

The Genetic Code

The Mechanism of Protein Synthesis

Recombinant DNA Techniques

Filters