Deck 15: Lipid Structure and Function

Question 1

Identify the $\omega$ -6 fatty acid.

A)
B)
C)
D)

Answer 1

Question 2

One advantage of using hydrogenation in the food industry is

A) decreased processing time.
B) reduction in heart disease.
C) increased shelf life.
D) decreased melting point.

Answer 2

increased shelf life.

Question 3

Identify the wax.

A)
B)
C)
D)

Answer 3

Question 4

Partial hydrogenation can result in the formation of

A) " $\omega$ -3 fatty acids."
B) " $\omega$ -6 fatty acids."
C) "cis double bonds."
D) "trans double bonds."

Question 5

Using common nomenclature, name the following fatty acid.

A) trans 14:1 ( $\Delta$ ⁷)
B) cis 14:1 ( $\Delta$ ⁷)
C) trans 14:7 ( $\Delta$ ¹)
D) cis 14:7 ( $\Delta$ ¹)

Question 6

Compared with a fatty acid, a wax

A) contains a glycerol backbone.
B) has long hydrocarbon chains with a carboxylate group.
C) has long hydrocarbon chains connected with an ester linkage.
D) contains a polar phosphate group.

Question 7

A fatty acid that has more than one double bond is referred to as

A) monosaturated.
B) monounsaturated.
C) polysaturated.
D) polyunsaturated.

Question 8

Classify the following fatty acid.

A) saturated
B) unsaturated
C) monounsaturated
D) polyunsaturated

Question 9

Predict the fatty acid with the highest melting point.

A)
B)
C)
D)

Question 10

Predict the structure of a fatty acid that is trans 18:2 ( $\Delta$ ^9,11).

A)
B)
C)
D)

Question 11

Using common nomenclature, name the following fatty acid.

A) trans 16:2 ( $\Delta$ ^11,13)
B) cis 16:2 ( $\Delta$ ^11,13)
C) trans 16:2 ( $\Delta$ ^3,5)
D) cis 16:2 ( $\Delta$ ^3,5)

Question 12

Identify the polyunsaturated fatty acid.

A)
B)
C)
D)

Question 13

Identify the $\omega$ -3 fatty acid.

A)
B)
C)
D)

Question 14

One disadvantage of using partial hydrogenation in the food industry is that

A) the shelf life of the oils is not as long.
B) trans fats are formed during the process.
C) the oils tend to become rancid and have foul odors.
D) the oils cost more than animal fats.

Question 15

Predict the structure of a fatty acid that is cis 16:1 ( $\Delta$ ⁹).

A)
B)
C)
D)

Question 16

Predict the fatty acid with the highest melting point.

A) trans 14:1 ( $\Delta$ ⁷)
B) cis 14:2 ( $\Delta$ ^7,9)
C) trans 14:2 ( $\Delta$ ^7,9)
D) cis 14:3 ( $\Delta$ ^7,9,11)

Question 17

Using common nomenclature, name the following fatty acid.

A) trans 18:1 ( $\Delta$ ^{1 0})
B) cis 18:1 ( $\Delta$ ^{1 0})
C) trans 18:1 ( $\Delta$ ⁸)
D) cis 18:1 ( $\Delta$ ⁸)

Question 18

Predict the fatty acid with the lowest melting point.

A) trans 14:1 ( $\Delta$ ⁷)
B) cis 14:2 ( $\Delta$ ^7,9)
C) trans 14:2 ( $\Delta$ ^7,9)
D) cis 14:3 ( $\Delta$ ^7,9,11)

Question 19

Predict the essential $\omega$ -6 fatty acid.

A) trans 18:2 ( $\Delta$ ^9,12)
B) cis 18:2 ( $\Delta$ ^9,12)
C) trans 18:2 ( $\Delta$ ^6,9)
D) cis 18:2 ( $\Delta$ ^6,9)

Question 20

Predict the structure of a fatty acid that is trans 16:1 ( $\Delta$ ⁹).

A)
B)
C)
D)

Question 21

Arrange the following steps of glucagon signaling in the correct order. 1. A hydrolysis reaction cleaves a fatty acid from the stored triacylglycerols to generate diacylglycerol and a fatty acid.
2) The regulatory protein G58 binds to adipose triglyceride lipase.
3) Perilipin is phosphorylated on the surface of lipid droplets.
4) Albumin transports the free fatty acid.
5) A GDP-GTP exchange stimulates cyclic AMP production by the enzyme adenylate cyclase.

A) 2, 5, 3, 4, 1
B) 5, 2, 4, 3, 1
C) 5, 3, 2, 1, 4
D) 2, 3, 5, 1, 4

Question 22

In addition to triacylglycerols, which other lipid synthesized in the liver is transported by VLDLs?

A) sphingophospholipid
B) cerebroside
C) ganglioside
D) cholesterol

Question 23

Spices such as eugenol are added to oils to enhance the flavor because of

A) hydrogen bonds.
B) dipole-dipole interactions.
C) hydrophilic interactions.
D) hydrophobic interactions.

Question 24

Chylomicrons are produced in

A) liver cells.
B) intestinal epithelial cells.
C) stomach cells.
D) adipocytes.

Question 25

Identify the lipase whose activity is regulated by protein G58.

A) colipase
B) monoacylglycerol lipase
C) hormone-sensitive lipase
D) adipose triglyceride lipase

Question 26

During the process of saponification, fatty acid molecules are released from triacylglycerols by treatment(s) with a strong

A) base.
B) acid.
C) base and heat.
D) acid and heat.

Question 27

The lipase-mediated release of fatty acids can always be expected to occur when a person is

A) reading a book.
B) watching TV.
C) running from a bear.
D) eating.

Question 28

In comparison with glycerophospholipids, the structure of cerebrosides contains a

A) fatty acid.
B) sphingosine.
C) choline.
D) steroid ring.

Question 29

Which particles transport triacylglycerols to adipose tissue for storage?

A) apolipoproteins
B) adipocytes
C) chylomicrons
D) perilipin

Question 30

The water-soluble enzyme in the small intestine that hydrolyzes the acyl ester bonds in triacylglycerols is

A) adipocyte.
B) albumin.
C) lipase.
D) colipase.

Question 31

Soap traps dirt particles in

A) triacylglycerols.
B) micelles.
C) steroids.
D) glycerophospholipids.

Question 32

VLDLs are produced in

A) liver cells.
B) intestinal epithelial cells.
C) stomach cells.
D) adipocytes.

Question 33

A wax is defined as

A) long chain fatty alcohols esterified to hydrocarbon chains.
B) three fatty acids linked to a glycerol backbone.
C) a long hydrocarbon chain with a carboxylate group at the end.
D) two fatty acids and a phosphate group linked to a glycerol backbone.

Question 34

Triacylglycerols are transported though the blood as

A) glycerophospholipids.
B) sphingolipids.
C) cerebrosides.
D) very low density lipoprotein particles.

Question 35

Chylomicrons contain a monolayer on the outside of the particle consisting of

A) cerebrosides and phospholipids.
B) cerebrosides and sphingolipids.
C) phospholipids and cholesterol.
D) cholesterol and sphingolipids.

Question 36

Which is the step in glucagon signaling where adipose triglyceride lipase mediates a reaction?

A) 1
B) 2
C) 3
D) 4

Question 37

The lipase-mediated release of fatty acids can always be expected to occur when a person is

A) hungry.
B) walking.
C) studying.
D) watching TV.

Question 38

The biosynthesis of triacylglycerols in animals uses which citrate cycle intermediate in the liver?

A) malate
B) acetyl-CoA
C) isocitrate
D) succinate

Question 39

Which step in glucagon signaling occurs in the G_{s $\alpha$} protein? 1. A hydrolysis reaction cleaves a fatty acid from the stored triacylglycerols to generate diacylglycerol and a fatty acid.
2) The regulatory protein G58 binds to adipose triglyceride lipase.
3) Perilipin is phosphorylated on the surface of lipid droplets.
4) Albumin transports the free fatty acid.
5) A GDP-GTP exchange stimulates cyclic AMP production by the enzyme adenylate cyclase.

A) 1
B) 2
C) 3
D) 5

Question 40

Free fatty acids released from adipose tissue are transported throughout the body by a carrier protein called

A) adipocyte.
B) albumin.
C) lipase.
D) colipase.

Question 41

In comparison with glycerophospholipids and sphingolipids, cholesterol contains a

A) fatty acid.
B) phosphate group.
C) glycerol moiety.
D) steroid ring.

Question 42

In comparison with gangliosides, the structure of phosphatidylcholine contains a

A) fatty acid.
B) sugar moiety.
C) glycerol moiety.
D) steroid ring.

Question 43

Which membrane lipids are derivatives of long chain amino alcohols synthesized from palmitate and serine?

A) phosphatidylinositol
B) phosphatidylcholine
C) sphingosines
D) phosphatidylethanolamine

Question 44

The total content of __________ is approximately the same in both the inner and outer layer of the plasma membrane of human erythrocytes.

A) phosphatidylinositol
B) sphingomyelin
C) phosphatidylcholine
D) cholesterol

Question 45

Lipid rafts are thought to be discrete membrane regions that contain high concentrations of

A) phosphatidylinositol.
B) gangliosides.
C) phosphatidylcholine.
D) cholesterol.

Question 46

One of the functions of the lipid rafts is to

A) act as a storage mechanism for fatty acids.
B) control fluidity of the membrane.
C) coordinate cell signaling.
D) maintain sodium levels in the cell.

Question 47

Which of the following amino alcohols act as the functional group attached to a phosphate in a glycerophospholipid?

A) methanolamine
B) ethanolamine
C) propanolamine
D) butanolamine

Question 48

Which of the following membranes would have the least amount of fluidity based on the following percentage of cholesterol in the membrane?

A) 10%
B) 25%
C) 30%
D) 40%

Question 49

The addition of phosphocholine to ceramides generates

A) glycerophospholipids.
B) gangliosides.
C) cerebrosides.
D) sphingomyelin.

Question 50

Compared with other areas of the membrane, lipid rafts contain more

A) sphingolipids.
B) phosphatidylcholine.
C) phosphatidylinositol.
D) gangliosides.

Question 51

Which missing enzyme results in Tay-Sachs disease?

A) "phospholipase A₂"
B) "sphingomyelinase"
C) " $\alpha$ -galactosidase A"
D) "hexosaminidase A"

Question 52

The inner layer of the plasma membrane of human erythrocytes contains mostly __________ lipids.

A) phosphatidylserine
B) ganglioside
C) phosphatidylcholine
D) sphingomyelin

Question 53

The outer layer of the plasma membrane of human erythrocytes contains mostly __________ lipids.

A) phosphatidylinositol
B) phosphatidylserine
C) phosphatidylcholine
D) phosphatidylethanolamine

Question 54

Which of the following membranes would have the greatest fluidity based on the following percentage of cholesterol in the membrane?

A) 10%
B) 25%
C) 30%
D) 40%

Question 55

Snake venom often secretes phospholipase A₂ enzymes, which cleave

A) glycerophospholipids.
B) ceramides.
C) sphingosines.
D) gangliosides.

Question 56

Which missing enzyme results in Niemann-Pick disease?

A) "phospholipase A₂"
B) "sphingomyelinase"
C) " $\alpha$ -galactosidase A"
D) "hexosaminidase A"

Question 57

Which type of fatty acid plays important roles in cell recognition such as in ABO blood groups?

A) sphingomyelins
B) gangliosides
C) cerebrosides
D) glycerophospholipids

Question 58

Which missing enzyme results in Fabry disease?

A) "phospholipase A₂"
B) "sphingomyelinase"
C) " $\alpha$ -galactosidase A"
D) "hexosaminidase A"

Question 59

Tay-Sachs disease, Fabry disease, and Niemann-Pick disease are all symptomatic because of

A) defects in sphingolipid metabolism.
B) improper glycan storage.
C) cleavage of glycerophospholipids.
D) reduced cholesterol synthesis.

Question 60

Which of the following amino alcohols act as the functional group attached to a phosphate in a glycerophospholipid?

A) lysine
B) serine
C) glycine
D) alanine

Question 61

Mineralocorticoids and glucocorticoids are synthesized in the

A) kidneys.
B) adrenal glands.
C) liver.
D) corpus luteum.

Question 62

Which eicosanoid regulates blood vessel constriction?

A) prostaglandin
B) prostacyclin
C) thromboxane
D) leukotriene

Question 63

Which eicosanoid controls platelet formation?

A) prostaglandin
B) prostacyclin
C) thromboxane
D) leukotriene

Question 64

7-Dehydrocholesterol is converted to cholecalciferol (Vitamin D₃) by

A) P450C1 hydroxylase.
B) P450C12 hydroxylase.
C) P450C25 hydroxylase.
D) ultraviolet light.

Question 65

Cortisol is a glucocorticoid that regulates

A) blood pressure.
B) ion transport in the kidneys.
C) testosterone.
D) liver metabolism.

Question 66

Inhibition of the COX-1 enzyme results in

A) reduced pain and fever.
B) reduced mucin secretion.
C) increased risk of heart disease.
D) increased platelet aggregation.

Question 67

Which eicosanoid acts as an inflammatory mediator that also regulates smooth muscle contraction?

A) prostaglandin
B) prostacyclin
C) thromboxane
D) leukotriene

Question 68

Which of the following molecules aid in the absorption of dietary lipids?

A) prostaglandin
B) cortisol
C) glycocholate
D) aldosterone

Question 69

Why do long chain, saturated fatty acids have a higher melting point than unsaturated fatty acids?

Question 70

Compare and contrast saturated, monounsaturated, and polyunsaturated fatty acids.

Question 71

Compared with the COX-2 enzyme, COX-1 has

A) a larger active site.
B) a smaller active site.
C) a more elongated three-dimensional structure.
D) more $\beta$ -barrels.

Question 72

What is partial hydrogenation? Outline the pros and cons of using partial hydrogenation in the food industry.

Question 73

25-Hydroxyvitamin D₃ is converted to 1,25-hydroxyvitamin D₃ by

A) P450C1 hydroxylase.
B) P450C12 hydroxylase.
C) P450C25 hydroxylase.
D) ultraviolet light.

Question 74

Which steroid hormone is synthesized in the corpus luteum?

A) cortisol
B) progesterone
C) testosterone
D) estradiol

Question 75

Which eicosanoid modulates the secretion of proteoglycans that protects the stomach lining from the effects of low pH?

A) prostaglandin
B) prostacyclin
C) thromboxane
D) leukotriene

Question 76

Which steroid hormone is synthesized in the ovaries?

A) cortisol
B) progesterone
C) testosterone
D) estradiol

Question 77

Using common nomenclature, name the following fatty acid structures.

a.
b.

c.

Question 78

Predict the following fatty acid structures.
a. cis 18:2 ( $\Delta$ ^9,12)
b. trans 18:1 ( $\Delta$ ⁹)
c. trans 20:2 ( $\Delta$ ^11,13)

Question 79

Vitamin D₃ is converted to 25-hydroxyvitamin D₃ in the cells.

A) skin
B) kidney
C) muscle
D) liver

Question 80

A patient is having problems regulating blood pressure and has poor kidney function. Which steroid could be responsible for this?

A) progesterone
B) cortisol
C) aldosterone
D) estradiol