Deck 23: Lipids

Question 1

Which molecule is a fatty acid?

A)CH₃COOH
B)CH₂=CHCOOH
C)(CH₃)₂CH(CH₂)₃COOH
D)CH₃(CH₂)₇CH=CH(CH₂)₇COOH
E)none of the above

Answer 1

CH₃(CH₂)₇CH=CH(CH₂)₇COOH

Question 2

Which of the following is not a biochemical function of waxes?

A)prevention of water loss by leaves
B)waterproofing of feathers in shore birds
C)energy storage for animals
D)structural materials in beehives
E)physical protection of mammalian ears

Answer 2

energy storage for animals

Question 3

Biomolecules can be classified as lipids on the basis of

A)a common structure consisting of long hydrocarbon chains.
B)the presence of many hydroxyl groups and at least one carbonyl group.
C)the presence of at least one amine group and one carboxylic acid group on each molecule.
D)the physical properties of odor,color,and melting point within certain guidelines.
E)the physical property of solubility in nonpolar organic solvents.

Answer 3

the physical property of solubility in nonpolar organic solvents.

Question 4

All of the following types of molecules can be classified as lipids except

A)triacylglycerols.
B)steroids.
C)glycoproteins.
D)eicosanoids.
E)sphingomyelins.

Question 5

Biomolecules classified as lipids are

A)polyhydroxy aldehydes or ketones,or compounds which produce those when hydrolyzed.
B)polymers of α-amino acids.
C)soluble in non-polar solvents.
D)six-membered rings with delocalized electrons.
E)polymers of diacids and diamines.

Question 6

The molecule shown can be classified as a(an)

A)steroid.
B)eicosanoid.
C)wax.
D)glycerophospholipid.
E)sphingolipid.

Question 7

Which molecule is a saturated fatty acid?

A)lauric acid
B)linoleic acid
C)arachidonic acid
D)butyric acid
E)oleic acid

Question 8

Substances originating in plant or animal material and soluble in non-polar organic solvents are classified as

A)carbohydrates.
B)lipids.
C)nucleic acids
D)proteins.
E)amino acids.

Question 9

Which molecule is an unsaturated fatty acid?

A)lauric acid
B)linoleic acid
C)myristic acid
D)butyric acid
E)stearic acid

Question 10

Which C₁₈ fatty acid is a solid at room temperature?

A)oleic acid
B)linoleic acid
C)linolenic acid
D)stearic acid
E)All will be solids at room temperature.

Question 11

Which molecule is a saturated fatty acid?

A)CH₃(CH₂)₁₄COOH
B)CH₃(CH₂)₇CH=CH(CH₂)₇COOH
C)CH₃CH=CHCH₂COOH
D)(CH₃)₂CH(CH₂)₃COOH
E)none of the above

Question 12

The chemical makeup of a wax is

A)a simple ester of a long chain alcohol and a fatty acid.
B)an ester of glycerol with three identical saturated fatty acids.
C)an ester of glycerol with three identical unsaturated fatty acids.
D)an ester of glycerol with three predominantly saturated fatty acids.
E)an ester of glycerol with three predominantly unsaturated fatty acids.

Question 13

Which molecule is not a fatty acid?

A)CH₃(CH₂)₁₄COOH
B)CH₃CH₂(CH=CHCH₂)₃(CH₂)₆COOH
C)(CH₃)₂CH(CH₂)₃COOH
D)CH₃(CH₂)₇CH=CH(CH₂)₇COOH
E)none of the above

Question 14

The chemical makeup of fats is

A)simple esters of long chain alcohols and fatty acids.
B)esters of glycerol with three identical saturated fatty acids.
C)esters of glycerol with three identical unsaturated fatty acids.
D)esters of glycerol with three predominantly saturated fatty acids.
E)esters of glycerol with three predominantly unsaturated fatty acids.

Question 15

Which molecule is an unsaturated fatty acid?

A)CH₃(CH₂)₁₄COOH
B)CH₃(CH₂)₇CH=CH(CH₂)₇COOH
C)CH₃CH=CHCH₂COOH
D)(CH₃)₂CH(CH₂)₃COOH
E)none of the above

Question 16

Triglycerides belong to which general class of organic molecules?

A)esters
B)alcohols
C)carboxylic acids
D)ketones
E)ethers

Question 17

The biochemical roles of lipids are

A)short-term energy storage,transport of molecules,and structural support.
B)storage of excess energy,component of cell membranes,and chemical messengers.
C)catalysis,protection against outside invaders,motion.
D)component of cell membranes,catalysis,and structural support.
E)neurotransmitters,hormones,transport of molecules.

Question 18

Which molecule is a polyunsaturated fatty acid?

A)CH₃(CH₂)₇CH=CH(CH₂)₇COOH
B)CH₂=CHCH=CHCOOH
C)CH₃CH₂(CH=CHCH₂)₃(CH₂)₆COOH
D)HOOCCH₂(CH=CHCH₂)₃CH₂COOH
E)none of the above

Question 19

Most naturally occurring monounsaturated fatty acids can be classified as which of the following?

A)D
B)L
C)cis
D)trans
E)none of the above

Question 20

The molecule shown can be classified as a(an)

A)steroid.
B)eicosanoid.
C)wax.
D)glycerophospholipid.
E)sphingolipid.

Question 21

The product of an esterification reaction between which of the following molecules would be an oil?
I.CH₃ (CH₂)₁₄COOH
II.CH₃ (CH₂)₇CHCH(CH₂)₇COOH
III.HOCH₂CH₂OH
IV.HOCH₂CH(OH)CH₂OH

A)I and IV
B)II and III
C)II and IV
D)I and III
E)I and II

Question 22

The chemical makeup of oils is

A)simple esters of long chain alcohols and fatty acids.
B)esters of glycerol with three identical saturated fatty acids.
C)esters of glycerol with three identical unsaturated fatty acids.
D)esters of glycerol with three predominantly saturated fatty acids.
E)esters of glycerol with three predominantly unsaturated fatty acids.

Question 23

The hydrocarbon end of a soap molecule is

A)hydrophilic and attracted to grease.
B)hydrophobic and attracted to grease.
C)hydrophilic and attracted to water.
D)hydrophobic and attracted to water.
E)neither hydrophobic nor hydrophilic.

Question 24

Oils are generally ________ at room temperature and are obtained from ________.

A)liquids; plants
B)liquids; animals
C)solids; plants
D)solids; animals
E)none of the above

Question 25

Soaps are ________.

A)alkali metal salts of long chain carboxylic acids
B)long chain fatty alcohols
C)esters of a long chain fatty alcohol with a long chain fatty acid
D)alkali metal salts of glycerol
E)B and D

Question 26

Fats are generally ________ at room temperature and are obtained from ________.

A)liquids; plants
B)liquids; animals
C)solids; plants
D)solids; animals
E)none of the above

Question 27

Sphingomyelins are composed of sphingosine,a fatty acid,phosphoric acid,and

A)choline.
B)glucose.
C)galactose.
D)inositol.
E)none of the above

Question 28

Use the terms hydrophobic,hydrophilic,and micelle to explain how a soap removes grease from fabric.

Question 29

In chemical terms,soaps can best be described as

A)simple esters of fatty acids.
B)mixed esters of fatty acids.
C)salts of carboxylic acids.
D)long chain acids.
E)bases formed from glycerol.

Question 30

Which reaction can be used to convert oils into fats?

A)hydrogenation
B)hydrolysis
C)esterification
D)saponification
E)dehydration

Question 31

Saturated triacylglycerols are usually ________ because ________.

A)liquids; they have relatively short fatty acid chains
B)liquids; their rigid fatty acid chains do not fit together closely
C)liquids; they contain impurities from their natural sources
D)solids; they have relatively long fatty acid chains
E)solids; their flexible fatty acid chains allow the molecules to fit together closely

Question 32

Describe the similarities and differences between soaps and emulsifying agents.

Question 33

The type of lipid that is predominant in cell membranes is

A)fats.
B)phospholipids.
C)waxes.
D)steroids.
E)leukotrienes.

Question 34

The product of an esterification reaction between which of the following molecules would be a fat?
I.CH₃(CH₂)₁₄COOH
II.CH₃(CH₂)₇CH=CH(CH₂)₇COOH
III.HOCH₂CH₂OH
IV.HOCH₂CH(OH)CH₂OH

A)I and IV
B)II and III
C)II and IV
D)I and III
E)I and II

Question 35

Which fatty acid composition will yield a triglyceride that will most likely be an oil?

A)3 palmitic acid units
B)2 palmitic acid and 1 oleic acid units
C)2 linoleic acid and 1 stearic acid units
D)3 stearic acid units
E)2 palmitic acid and 1 stearic acid units

Question 36

Unsaturated triacylglycerols are usually ________ because ________.

A)liquids; they have relatively short fatty acid chains
B)liquids; the kinks in their fatty acid chains prevent their fitting together closely
C)liquids; they contain impurities from their natural sources
D)solids; they have relatively long fatty acid chains
E)solids; the similar zig-zag shape of their fatty acid chains allows them to fit together closely

Question 37

Fats and oils can be referred to by the general term ________ because ________.

A)phospholipids; they are formed when any one of the three ester groups is replaced by a phosphate group
B)triglycerides; they are formed when any one of the three functional groups of glycerol reacts with a fatty acid
C)triacylglycerols; they are formed by reaction of 1,2,3-propanetriol with three fatty acids
D)soaps; they can undergo saponification reactions
E)steroids; they have a specific tetracyclic ring structure

Question 38

The saponification reaction used to form soaps can be more specifically described as

A)acid hydrolysis.
B)basic hydrolysis.
C)hydrogenation.
D)dehydrogenation.
E)dehydration.

Question 39

When a lipid is hydrolyzed to form a mixture of fatty acids,glycerol and phosphate as its products,the lipid is classified as

A)simple lipid.
B)complex lipid.
C)nonsaponifiable.
D)miscellaneous.

Question 40

A phospholipid with the phosphate ester group bonded to choline would be classified as a

A)cephalin.
B)lecithin.
C)sphingomyelin.
D)cerebroside.
E)ganglioside.

Question 41

Sphingomyelin is made of

A)sphingosine,a fatty acid and phosphoryl choline.
B)sphingosine,a fatty acid and a trisaccharide.
C)sphingosine,a fatty acid and glucose.
D)glycerol and a fatty acid.
E)glycerol,fatty acid and phosphate.

Question 42

The basic structure of cell membranes consists of

A)protein micelles studded with phospholipids.
B)protein bilayers studded with phospholipids.
C)one protein layer and one phospholipid layer.
D)phospholipid micelles studded with proteins.
E)phospholipid bilayers studded with proteins.

Question 43

Upon hydrolysis,which of the following lipid types would yield a carbohydrate as a product?

A)lecithins
B)glycolipids
C)cephalins
D)phospholipids

Question 44

The difference in chemical structure between cerebrosides and gangliosides is that gangliosides

A)have larger fatty acid molecules than cerebrosides.
B)contain more complex carbohydrates than cerebrosides.
C)are found in many kinds of cells,but cerebrosides mainly in brain cells.
D)are based on glycerol and cerebrosides on sphingosine.
E)are based on sphingosine and cerebrosides on glycerol.

Question 45

Phosphoglycerides differ from glycerides in that one of the hydroxyl groups of the glycerol is esterified with

A)phosphoric acid.
B)phosphorous.
C)choline.
D)serine.

Question 46

Sketch a lipid bilayer and identify its hydrophobic and hydrophilic portions.

Question 47

Glycolipids are similar in structure to sphingomyelins,except that the phosphate group has been replaced by a(an)

A)choline derivative.
B)carbohydrate.
C)fatty acid.
D)amino acid.
E)nucleic acid.

Question 48

The function of glycoproteins and glycolipids in cell membranes is to

A)vary the fluidity of the membrane as needed.
B)mediate interactions between the cell and outside agents.
C)provide channels for facilitated diffusion.
D)provide channels for active transport.
E)act as energy sources for active transport.

Question 49

Phospholipids differ from fats and oils by having

A)one of the fatty acid ester linkages replaced by a phosphate ester linkage.
B)one of the fatty acid ester linkages replaced by an amine group.
C)cyclic ester structures instead of the three-carbon backbone.
D)a molecule of glucose bonded to the three-carbon backbone.
E)a molecule of galactose bonded to the three-carbon backbone.

Question 50

Cholesterol is implicated as a potential cause of atherosclerosis because it

A)acts as a precursor to steroid hormones.
B)takes part in the reactions that produce bile acids.
C)maintains structure because of its flat rigid characteristics.
D)attracts hydrophobic molecules to form solid deposits.
E)none of the above

Question 51

A sphingomyelin includes all of the following components except

A)amino alcohol.
B)phosphate group.
C)sphingosine.
D)glycerol.
E)fatty acid.

Question 52

Lecithin is commonly used as a(an)

A)emulsifying agent.
B)lubricant.
C)drying agent.
D)precipitating agent.
E)dispersant.

Question 53

A certain glycerophospholipid is made of glycerol,two fatty acids,a phosphate and ethanolamine.Which components do carboxylic ester linkages connect?

A)the fatty acids and phosphate
B)glycerol and ethanolamine
C)glycerol and the fatty acids
D)phosphate and ethanolamine
E)There are no carboxylic ester linkages.

Question 54

Which statement about cholesterol is not correct?

A)It is an essential component of cell membranes.
B)It is the precursor for steroid hormones.
C)It is the precursor for bile acids and salts.
D)It cannot be synthesized by the body.
E)It is soluble in non-polar solvents.

Question 55

The molecule shown can be classified as a(an)

A)wax.
B)glycerophospholipid.
C)sphingolipid.
D)glycolipid.
E)triacylglycerol.

Question 56

The carbohydrate portion of a glycolipid extends ________ in order to allow the molecule to function as a ________.

A)into the extracellular fluid; receptor site
B)into the extracellular fluid; transport channel
C)into the intracellular fluid; transport channel
D)into the intracellular fluid; receptor site
E)laterally within the bilayer; fluid membrane

Question 57

Steroids are

A)simple esters of long chain alcohols and fatty acids.
B)esters of glycerol with three predominantly saturated fatty acids.
C)esters of glycerol with three predominantly unsaturated fatty acids.
D)based on a tetracyclic ring system with substituents at various positions.
E)based on a system composed of four adjacent aromatic rings with substituents at various positions.

Question 58

All of the following are components of a cell membrane except

A)liposomes.
B)integral proteins.
C)peripheral proteins.
D)glycoproteins.
E)cholesterol.

Question 59

The function of cholesterol in a cell membrane is to

A)act as a precursor to steroid hormones.
B)take part in the reactions that produce bile acids.
C)maintain structure because of its flat rigid characteristics.
D)attract hydrophobic molecules to form solid deposits.
E)none of the above

Question 60

Steroids are classified as lipids because they have a distinguishing feature that they

A)dissolve in nonpolar solvents.
B)are present in biological membranes.
C)can be saponified.
D)have a ring structure.

Question 61

Match the following.
unsaturated

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 62

Local hormones ________.

A)are short-lived
B)can be prostaglandins
C)can be leukotrienes
D)act near their point of synthesis
E)all of the above

Question 63

The compound that is the immediate precursor to the prostaglandins is

A)cholesterol.
B)oleic acid.
C)stearic acid.
D)arachidonic acid.
E)leukotriene.

Question 64

Compare the three mechanisms for moving materials across cell membranes.Be sure to mention gradients,energy considerations,actual method of transport,and types of materials transported in your answer.

Question 65

The process of transport across cell membranes which costs biochemical energy is

A)simple diffusion.
B)facilitated diffusion.
C)active transport.
D)osmosis.
E)none of the above

Question 66

Which statement about eicosanoids is not correct?

A)The parent molecule,arachidonic acid,contains 20 carbon atoms.
B)Linolenic acid is a precursor to arachidonic acid.
C)All of the molecules in this category are unsaturated.
D)Eicosanoids function as "local hormones," acting as short-term chemical messengers.
E)none of the above

Question 67

Match the following.
facilitated diffusion

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 68

Prostaglandins

A)are produced by prostate gland and have a hormone function.
B)are involved in the reproductive processes of the human female.
C)are inhibited by the drug aspirin.
D)All of these are correct statements.
E)None of these are correct statements.

Question 69

The process of moving solutes into or out of a cell against the natural concentration gradient is called

A)active transport.
B)passive transport.
C)facilitated diffusion.
D)diffusive transport.
E)allotropic migration.

Question 70

Match the following.
hydrophilic

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 71

Match the following.
active transport

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 72

Match the following.
hydrophobic

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 73

Which choice is an example of a material that is transported across cell membranes by active transport?

A)cholesterol
B)K⁺
C)glucose
D)oxygen
E)carbon dioxide

Question 74

Eicosanoids function as

A)sex hormones.
B)thyroid hormones.
C)local hormones.
D)neurotransmitters.
E)membrane components.

Question 75

Which substance will not be transported into a cell by simple diffusion?

A)CO₂
B)O₂
C)estrogen
D)cortisone
E)epinephrine

Question 76

A protein which extends completely through the cell membrane is referred to as a(an)

A)liposome.
B)integral protein.
C)peripheral protein.
D)glycoprotein.
E)cholesterol.

Question 77

Match the following.
saturated

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 78

Match the following.
simple diffusion

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances

Question 79

Match the following.
polyunsaturated

A)describes fatty acids that have mostly single but at least one double carbon-carbon bond
B)describes the non-polar portion of a molecule that does not interact with water or other polar substances
C)a process of transport in which integral proteins change shape to allow a substance to cross a cell membrane
D)describes fatty acids that do not have any carbon-carbon double bonds
E)a process of transport that costs energy because the flow is against the concentration gradient
F)describes fatty acids that have mostly single but more than one double carbon-carbon bond
G)a process of transport in which substances cross a membrane based on concentration differences without the expenditure of energy
H)describes the polar portion of a molecule that interacts readily with water or other polar substances