Deck 21: Lipids

Question 1

Which alcohol is a component of all triglycerides?

A) 1,2,3-butanetriol
B) ethylene glycol
C) glycerol
D) none of these

Answer 1

C

Question 2

Which of the following is true of the unsaturated fatty acids found in triglycerides?

A) The double bond generally has the cis configuration.
B) The double bond generally has the trans configuration.
C) There are approximately equal number of cis and trans arrangements.
D) They always contain more than one double bond.

Answer 2

A

Question 3

Which of the following fatty acids is(are) likely to be found in a triglyceride?

A) CH₃(CH₂)₁₆COOH
B) CH₃(CH₂)₂₄COOH
C) both a and b
D) neither a nor b

Answer 3

A

Question 4

What is the function of secondary messengers such as prostaglandins?

A) carry a message from one part of a cell to another part of the cell
B) deliver signals from one part of the body to another
C) mediate hormonal responses
D) none of these

Question 5

Triglycerides belong to which class of compounds?

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

Question 6

Which of the following is true of most fatty acids found triglycerides?

A) they are branched
B) they contain 10 to 20 carbon atoms
C) they contain an odd number of carbon atoms
D) none of the above

Question 7

Which of the following are primary messengers?

A) prostaglandins
B) steroid hormones
C) thromboxanes
D) all of these

Question 8

Which of the following is used to define lipids?

A) the presence of a specific functional group
B) their chemical structure
C) their insolubility in water
D) none of these

Question 9

Which of the following fatty acids is(are) likely to be found in a triglyceride?

A) CH₃(CH₂)₁₅COOH
B) CH₃(CH₂)₁₆COOH
C) both a and b
D) neither a nor b

Question 10

Lipids perform which of the following functions?

A) They store energy within fat cells.
B) They serve as chemical messengers.
C) They serve as membrane components.
D) All of the above are functions of lipids.

Question 11

Which of the following is true of most fatty acids found in triglycerides?

A) They are unbranched.
B) They contain more than 20 carbon atoms.
C) They contain an odd number of carbon atoms.
D) none of the above

Question 12

In addition to the carboxyl group, which of the following functional groups is found in the fatty acids found in triglycerides?

A) amino
B) carbonyl
C) hydroxyl
D) none of these

Question 13

What is the function of a steroid hormone primary messenger?

A) carry a message from one part of a cell to another part of the cell
B) deliver signals from one part of the body to another
C) either (a) or (b), depending on the specific hormone
D) neither (a) nor (b)

Question 14

Which of the following are secondary messengers?

A) prostaglandins
B) thromboxanes
C) both a and b
D) neither a nor b

Question 15

Which of the following fatty acids is(are) likely to be found in a triglyceride?

A) CH₂(CH₂)₁₅COOH
B) CH₃(CH₂)₂₄COOH
C) both a and b
D) neither a nor b

Question 16

How many different triglycerides can be formed when glycerol combines with one molecule of oleic acid, one molecule of palmitic and one molecule of stearic acid?

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

Question 17

What is the IUPAC name of glycerol?

A) 1,2-ethanediol
B) 1,2-propanediol
C) 1,3-propanediol
D) 1,2,3-propanetriol

Question 18

Which of the following is true about the energy storage capabilities of lipids as compared with that of carbohydrates?

A) Burning both lipids and carbohydrates produce about 4 kcal/g.
B) Burning both lipids and carbohydrates produce about 9 kcal/g.
C) Burning carbohydrates produces about 4 kcal/g, but burning lipids produces about 9 kcal/g.
D) Burning carbohydrates produces about 9 kcal/g, but burning lipids produces only about 4 kcal/g.

Question 19

Which of the following explains the insolubility of lipids in water?

A) Lipids are polar molecules.
B) The polar portion of lipids is much larger than the nonpolar portion.
C) The polar portion of lipids is much smaller than the nonpolar portion.
D) The polar and nonpolar portions of lipids are of comparable size.

Question 20

Lipids are divided into how many structural classes?

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

Question 21

Which of the following is true of linoleic acid?

A) It is an essential, saturated fatty acid.
B) It is an essential, unsaturated fatty acid.
C) It is not an essential fatty acid, but is a saturated fatty acid.
D) It is not an essential fatty acid, but is an unsaturated fatty acid.

Question 22

Which of the following is true of oleic acid?

A) It is an essential, saturated fatty acid.
B) It is an essential, unsaturated fatty acid.
C) It is not an essential fatty acid, but is a saturated fatty acid.
D) It is not an essential fatty acid, but is an unsaturated fatty acid.

Question 23

Which of the following is true of pure fats and oils?

A) They have color, but neither odor nor taste.
B) They have odor, but neither color nor taste.
C) They have taste, but neither odor nor color.
D) They are colorless, odorless and tasteless.

Question 24

In glycerophospholipids where is the phosphate group attached to glycerol?

A) at the middle carbon only
B) at a terminal carbon only
C) at either the middle or a terminal carbon
D) at both the middle and a terminal carbon

Question 25

If a triglyceride contains linoleic, linolenic and oleic acids how many moles of hydrogen are required to fully hydrogenate one mole of this triglyceride?

A) 3
B) 4
C) 5
D) 6

Question 26

Which of the following is found in all complex lipids?

A) a fatty acid
B) glycerol
C) phosphate
D) all of these

Question 27

If a triglyceride contains linoleic, linolenic and stearic acids how many moles of hydrogen are required to fully hydrogenate one mole of this triglyceride?

A) 3
B) 4
C) 5
D) 6

Question 28

Waxes belong to which class of compounds?

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

Question 29

Which of the following best describes the components of phospholipids?

A) glycerol, one fatty acid, two phosphate groups, and an alcohol
B) glycerol, two fatty acids, a phosphate group, and an alcohol
C) either of these, depending on the identity of the phospholipid
D) none of the above

Question 30

Which of the following linkages is found in glycerophospholipids?

A) glycerol−fatty acid−phosphate
B) glycerol−phosphate−fatty acid
C) phosphate−glycerol−alcohol
D) none of the above

Question 31

Which of the following linkages is found in sphingolipids?

A) sphingosine−choline−phosphate
B) sphingosine−phosphate−choline
C) phosphate−sphingosine−choline
D) none of the above

Question 32

Which of the following type of reaction is involved in saponification?

A) condensation
B) dehydration
C) hydrogenation
D) hydrolysis

Question 33

What is the minimum number of double bonds which must be present in a polyunsaturated fat or oil?

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

Question 34

Which of the following is found in glycolipids but not in other complex lipids?

A) a carbohydrate
B) a fatty acid
C) sphingosine
D) None, all these are found in both types of lipids.

Question 35

Which of the following is a reactant in a saponification reaction?

A) a strong acid
B) a weak acid
C) a strong base
D) a weak base

Question 36

Which of the following triglycerides is most likely to be a fat?

A) one which contains relatively short chain saturated fatty acids
B) one which contains relatively short chain unsaturated fatty acids
C) one which contains long chain saturated fatty acids
D) one which contains long chain unsaturated fatty acids

Question 37

What do we mean by an essential fatty acid?

A) a fatty acid which the body needs so it can synthesize other fatty acids
B) a fatty acid which must be part of our diets since we cannot synthesize it
C) both a and b
D) neither a nor b

Question 38

Which of the following alcohols could be the alcohol portion of a wax?

A) ethylene glycol, C₂H₄(OH)₂
B) glycerol, C₃H₅(OH)₃
C) 1-triacontanol, C₃₀H₆₁OH
D) none of these

Question 39

Which of the following reactions is the source of trans fatty acids found in some processed foods?

A) condensation
B) dehydration
C) hydrogenation
D) hydrolysis

Question 40

Which of the following alcohols can be found in glycerophospholipids?

A) choline
B) serine
C) inositol
D) all of these

Question 41

Lipid membranes have how many layers?

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

Question 42

Which of the following is true of all lecithins?

A) Their fatty acids are all saturated.
B) Their fatty acids are all unsaturated.
C) There is always a phosphate group bound to carbon 1 of glycerol.
D) There is always an unsaturated fatty acid bound to carbon 1 of glycerol.

Question 43

Which of the following is a function of unsaturated fatty acids in membranes?

A) They give the interior of the membrane liquid-like structure.
B) They provide a site for chemical reactions to occur.
C) both a and b
D) neither a nor b

Question 44

Which of the following is the polar portion of a sphingolipid?

A) phosphorylcholine
B) phosphorylethanolamine
C) phosphorylinositol
D) phosphorylserine

Question 45

Which of the following provide a mechanism for the transport of ions and polar molecules through a membrane?

A) active transport
B) diffusion
C) both a and b
D) neither a nor b

Question 46

Which of the following provide a mechanism for the transport of ions and polar molecules through a membrane?

A) active transport
B) specific channels
C) both a and b
D) neither a nor b

Question 47

Some glycerophospholipids are commonly called lecithins. Which of the following is found in all lecithins?

A) choline
B) ethanolamine
C) inositol
D) serine

Question 48

Which of the following is choline?

A) HOCH₂CH₂NH₂
B)
C) [HOCH₂CH₂N(CH₃)₃] ⁺
D) none of these

Question 49

Which class of glycerophospholipids can be phosphorylated to yield molecules which serve as signaling molecules?

A) cephalins
B) lecithins
C) phosphatidylinositols
D) all of these

Question 50

Which of the following correctly describes membrane proteins?

A) They are suspended on the surface of the membrane.
B) They are partly embedded in the bilayer.
C) They pass completely through the bilayer.
D) Any of the above, depending on the specific membrane protein.

Question 51

Which of the following is found in cephalins?

A) choline
B) ethanolamine
C) inositol
D) none of these

Question 52

Which components of a sphingolipid are collectively known as a ceramide?

A) the fatty acid and phosphate
B) the fatty acid and sphingosine
C) phosphate and choline
D) phosphate and sphingosine

Question 53

Which of the following is the name of small intracellular structures surrounded by lipid membranes?

A) alleles
B) microcells
C) organelles
D) none of these

Question 54

Which of the following are glycerophospholipids?

A) cephalins
B) lecithins
C) phosphatidylinositols
D) all of these

Question 55

Which of the following provide a mechanism for the transport of nonpolar molecules through a membrane?

A) active transport
B) diffusion
C) specific channels
D) all of these

Question 56

Which of the following is found in cephalins?

A) choline
B) inositol
C) serine
D) none of these

Question 57

Which of the following describes the distribution of the polar and nonpolar portions of lipids in the lipid bilayer?

A) Both polar heads are on the inside of the bilayer and both hydrophobic tails are on the outside of the bilayer.
B) Both polar heads are on the outside of the bilayer and both hydrophobic tails are on the inside of the bilayer.
C) Both the inside and outside of the bilayer consist of alternating polar heads and nonpolar tails.
D) Some polar heads are on the inside of the bilayer and some are on the outside; the hydrophobic tails are similarly distributed.

Question 58

What type of bond connects the fatty acid to sphingosine in sphingolipids?

A) amide
B) ester
C) ether
D) none of these

Question 59

Myelin, the coating of nerve axons, is which type of lipid?

A) cephalin
B) lecithin
C) simple lipid
D) sphingolipid

Question 60

Which of the following is true of all glycerophospholipids?

A) Their fatty acids are all saturated.
B) Their fatty acids are all unsaturated.
C) There is always a saturated fatty acid bound to carbon 2 of glycerol.
D) There is always an unsaturated fatty acid bound to carbon 2 of glycerol.

Question 61

How many rings are associated with the steroid structure?

A) 3
B) 4
C) 5
D) 6

Question 62

Which of the following linkages can be found in cerebrosides?

A) β-galactosidic
B) β-glucosidic
C) either a or b
D) neither a nor b

Question 63

How many different types of lipoproteins are associated with cholesterol transport?

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

Question 64

Where is cholesterol synthesized?

A) in the liver
B) in the pancreas
C) in the spleen
D) in none of these

Question 65

Which of the following are glycolipids?

A) cerebrosides
B) gangliosides
C) both a and b
D) neither a nor b

Question 66

Which of the following are glycolipids?

A) ceramides
B) endorphins
C) enkephalins
D) gangliosides

Question 67

Examine the following structure. If this substance was subjected to hydrolysis in the presence of NaOH, which of the following describes the products of this reaction?

A) 1 soap and glycerol
B) 2 different soaps and glycerol
C) 3 different soaps and glycerol
D) This substance will not undergo hydrolysis in the presence of a base.

Question 68

Which of the following are glycolipids?

A) ceramides
B) endorphins
C) enkephalins
D) none of these

Question 69

How many carbon atoms are associated with the steroid structure?

A) 15
B) 16
C) 17
D) 18

Question 70

Which of the following is not found in cerebrosides?

A) an amide linkage
B) a carbohydrate
C) a hydroxyl group
D) a phosphate group

Question 71

Which of the following linkages can be found in cerebrosides?

A) α-galactosidic
B) α-glucosidic
C) both a and b
D) neither a nor b

Question 72

Which of the following linkages can be found in cerebrosides?

A) α-fructosidic
B) β-fructosidic
C) α-glucosidic
D) β-glucosidic

Question 73

In cholesterol, to which ring of the steroid system is the hydroxyl group attached?

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

Question 74

Which of the following structural arrangements is the steroid structure?

A)
B)
C)
D)

Question 75

Which of the following is contains free cholesterol?

A) HDL
B) gallstones
C) LDL
D) all of these

Question 76

Which of the following linkages can be found in cerebrosides?

A) α-glucosidic
B) β-glucosidic
C) both a and b
D) neither a nor b

Question 77

Examine the following structure. If this substance was subjected to hydrogenation, how many moles of H₂ would be consumed per mole of this reactant?

A) 1 mol
B) 2 mol
C) 3 mol
D) 4 mol
E) This substance will not react with H₂.

Question 78

Which of the following are glycolipids?

A) ceramides
B) cerebrosides
C) endorphins
D) enkephalins

Question 79

Gaucher's disease is associated with which of the following?

A) the inability of synthesize glucocerebrosides
B) the inability to store sufficient glucocerebrosides
C) an over accumulation of glucocerebrosides
D) any of the above, depending on the patient

Question 80

Cholesterol is used as which of the following?

A) a component of plasma membranes
B) a starting material for the synthesis of other steroids
C) a starting material for the synthesis of bile salts
D) all of these