Deck 29: Lipid Synthesis

Question 1

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

Answer 1

phosphorylcholine

Question 2

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
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
In mammalian cells, phosphatidate is synthesized in the outer mitrochondrial membrane and the ___________________.

Answer 2

endoplasmic reticulum

Question 3

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
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
All of the carbons in cholesterol are derived from the metabolite _______________.

Answer 3

j

Question 4

___________________ is the major carrier of cholesterol esters in the blood.

Question 5

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
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
In mammals, the _______________ is the major site of triacylglycerol synthesis.

Question 6

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

Question 7

A(n) _________________ is composed of a fatty acid linked to sphingosine via an amide bond.

Question 8

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
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
_______________ is the primary bile salt.

Question 9

___________________ is the 30-carbon (triterpene) precursor of cholesterol.

Question 10

___________________ is a nine-carbon sugar that is a component of the gangliosides.

Question 11

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
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
_______________: The derivative of cholesterol that is the precursor of the steroid hormones.

Question 12

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

Question 13

Vitamin D3 is converted into ___________________, which is an active hormone that functions as a transcription factor.

Question 14

The synthesis of ___________________ is the committed step in cholesterol biosynthesis.

Question 15

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
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
The reduction of the metabolite _______________ supplies glycerol 3-phosphate for acylglycerol synthesis.

Question 16

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

Question 17

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

Question 18

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

Question 19

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

Question 20

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

Question 21

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

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

Question 22

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

Question 23

The starting materials necessary to synthesize sphingosine are:

A) palmitoyl CoA and serine.
B) acetyl CoA and glycine.
C) palmitoyl CoA and aspartate.
D) acetyl CoA and glutamine.
E) None of the above.

Question 24

Respiratory distress syndrome is caused by a failure in the biosynthetic pathway of:

A) sphingosine.
B) gangliosides.
C) dipalmitoyl phosphatidyl choline.
D) cholesterol.
E) bile salts.

Question 25

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

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

Question 26

HMG CoA is synthesized from acetyl CoA and:

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

Question 27

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

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

Question 28

Tay Sachs disease is caused by an inability to degrade:

A) sphingosine.
B) gangliosides.
C) dipalmitoyl phosphatidyl choline.
D) ceramide.
E) None of the above.

Question 29

In a ganglioside, what links the oligosaccharide to the hydroxyl of the ceramide?

A) stearic acid
B) glucose
C) choline
D) sialic acid
E) None of the above.

Question 30

The highest concentration of sphingolipids is found in the:

A) central nervous system.
B) lymph system.
C) serum.
D) All of the above.
E) None of the above.

Question 31

What are the causes and symptoms of familial hypercholesterolemia?

Question 32

Why is phosphatidyl serine considered a class of molecules, and not one type?

Question 33

Phosphatidate is formed from:

A) glycerol 3-phosphate and two fatty acyl CoA's.
B) glycerol and two free fatty acids.
C) pyruvate and triacylglycerol.
D) glycerol and two fatty acyl CoA's.
E) None of the above.

Question 34

Which of the following is the common precursor for both the phosphatidyl inositols and triacylglycerols?

A) diacylglycerol
B) inosinic acid
C) phosphatidate
D) CDP-diacylglycerol
E) None of the above.

Question 35

Hydroxylation of cholesterol by cytochrome P450 requires:

A) NADPH.
B) activated O2.
C) PLP.
D) A and B.
E) A and C.

Question 36

The LDL receptors on the plasma membrane are localized in coated pits that contain the receptors of which of the following proteins?

A) clathrin
B) lipoprotein A
C) adrenodoxin
D) HMG-CoA reductase
E) sterol regulatory element binding protein (SREBP)

Question 37

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

Question 38

What is the role of CTP in the synthesis of a phospholipid?

Question 39

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

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

Question 40

The role of lipoprotein particles is to:

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

Question 41

What is the role of phosphatidyl choline in the synthesis of sphingomyelin?

Question 42

What are the three stages of cholesterol synthesis?

Question 43

What are bile salts?

Question 44

What are the steps in LDL uptake into cells?

Question 45

Describe the various ways that 3-hydroxy-3-methylglutaryl CoA reductase is regulated, including both gene expression and enzyme regulation.

Question 46

How do blood levels of lipoproteins serve diagnostic purposes?

Question 47

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

Question 48

How are gangliosides synthesized?

Question 49

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

Question 50

List the types of lipoprotein particles and give the primary physiological role of the lipoprotein.