Deck 25: Lipids

Question 1

Which of the following terms best describes the compound below?

A) a wax
B) a saturated triglyceride
C) a terpene
D) a prostaglandin
E) a lecithin

Answer 1

a saturated triglyceride

Question 2

What group of lipids are esters of long-chain fatty acids and long-chain alcohols?

Answer 2

waxes

Question 3

Which of the following is a complex lipid?

A) testosterone
B) tristearin
C) arachidic acid
D) sodium palmitate
E) b-carotene

Answer 3

tristearin

Question 4

Which of the following terms best describes the compound below?
CH₃(CH₂)₁₂CO₂H

A) a triglyceride
B) a fatty acid
C) a wax
D) a prostaglandin
E) a phosphatidic acid

Question 5

Is cholesterol an example of a simple lipid or a complex lipid? Explain briefly.

Question 6

Are triglycerides simple lipids? Explain.

Question 7

Biodiesel is formed by ________.

A) saponification of a triglyceride
B) esterification of a triglyceride
C) saponification of a prostaglandin
D) hydrolysis of a wax

Question 8

When spermaceti is heated in aqueous potassium hydroxide,
and
are formed. Provide the structure of spermaceti.

Question 9

In the formation of a triacylglyceride, what two functional groups chemically combine?

A) carboxylic acid and an amine
B) carboxylic acid and an alcohol
C) alcohol and an aldehyde
D) alcohol and a ketone
E) two different alcohols

Question 10

Which of the following lipids is an example of a simple lipid?

A) fat
B) terpene
C) oil
D) wax
E) none of the above

Question 11

Which of the terms below best describes biodiesel?

A) fatty acid
B) fatty ester of methanol
C) wax
D) trigylceride

Question 12

Define lipid.

Question 13

Which of the following peaks would one expect to observe as a major, strong peak in the IR spectrum of a lipid wax?

A) 3200-3500 cm^-1
B) 2710 cm^-1
C) 2200 cm^-1
D) 1730 cm^-1
E) 1620 cm^-1

Question 14

Which of the following terms best describes the compound below?
CH₃(CH₂)₇CH
CH(CH₂)₇CO₂H

A) an unsaturated fatty acid
B) a triglyceride
C) a synthetic detergent
D) a micelle
E) isoprene

Question 15

Oleic acid is an example of ________ fatty acid. A molecule of oleic acid contains a single carbon-carbon double bond and ________ carbon atoms.

A) an unsaturated; 18
B) an unsaturated; 9
C) a saturated; 52
D) a saturated; 18
E) a saturated; 9

Question 16

________ lipids are those that can be easily hydrolyzed to simpler constituents.

Question 17

How many molecules of fatty acid are needed to produce one molecule of a fat or oil?

A) 1
B) 1.5
C) 2
D) 3
E) 6

Question 18

What IR stretch would most readily distinguish carnauba wax from paraffin wax?

Question 19

Name two of the three predominant groups of simple lipids.

Question 20

Which of the following terms best describes the compound below?
CH₃(CH₂)₂₆CO₂CH₂(CH₂)₃₂CH₃

A) a fat
B) an oil
C) a terpene
D) an unsaturated triglyceride
E) a wax

Question 21

Lauric acid has the formula CH₃(CH₂)₁₀CO₂H. Provide the structure of the triglyceride which was formed from three equivalents of lauric acid.

Question 22

Which of the following fatty acids has the lowest melting point?

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

Question 23

What does the term polyunsaturated mean when used to describe a triglyceride?

Question 24

Which of the following oils has the highest percentage of saturated fatty acid?

A) herring oil
B) olive oil
C) soybean oil
D) canola oil

Question 25

Which of the following oils would consume the greatest number of equivalents of hydrogen when subject to catalytic hydrogenation?

A) corn oil
B) olive oil
C) canola oil
D) linseed oil

Question 26

Which of the following is an unsaturated fatty acid?

A) adipic acid
B) linoleic acid
C) stearic acid
D) palmitic acid
E) oxalic acid

Question 27

What reagent is needed to convert CH₃(CH₂)₁₄CH₂OH to CH₃(CH₂)₁₄CHO?

Question 28

If triolein was transesterified with methanol under basic conditions to form biodiesel, draw the products of this reaction.

Question 29

Which of the following statements correctly describe(s) the relationship between the structure of a fatty acid and its melting point?

A) Saturated fatty acids have melting points that increase gradually with their molecular weights.
B) The presence of a trans double bond in the fatty acid has a greater effect on its melting point than does the presence of a cis double bond.
C) As the number of double bonds in a fatty acid increases, its melting point decreases.
D) both A and C
E) A, B, and C

Question 30

Name the compound whose formula is CH₃(CH₂)₁₂CO₂H.

Question 31

Which of the following fatty acids has the highest melting point?

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

Question 32

Which best describes the lipid shown below?

A) wax
B) triglyceride
C) saturated fatty acid
D) unsaturated fatty acid
E) lecithin

Question 33

What reagent is needed to convert CH₃(CH₂)₁₄CO₂H to CH₃(CH₂)₁₄CH₂OH?

Question 34

Why are fats more efficient sources of long-term energy than carbohydrates?

Question 35

Which best describes the lipid shown below?

A) wax
B) triglyceride
C) saturated fatty acid
D) unsaturated fatty acid
E) lecithin

Question 36

What reagent is needed to convert CH₃(CH₂)₁₄CO₂H to CH₃(CH₂)₁₄COCl?

Question 37

Which of the following oils is the least polyunsaturated?

A) linseed oil
B) corn oil
C) olive oil
D) soybean oil
E) canola oil

Question 38

Which best describes the lipid shown below?

A) wax
B) triglyceride
C) saturated fatty acid
D) unsaturated fatty acid
E) lecithin

Question 39

Which of the following oils has the highest composition of one single fatty acid?

A) herring oil
B) olive oil
C) soybean oil
D) canola oil

Question 40

Which reagent below could best be used to distinguish from

A) NaOH, H₂O
B) Ag(NH₃)₂⁺
C) H₂Cr₂O₇
D) Br₂/CCl₄
E) NH₃

Question 41

How is a fat distinguished from an oil, (a) based on a physical property difference and (b) based on a difference in molecular structure?

Question 42

What is a trans fat and how are they usually formed?

Question 43

How would you prepare CH₃(CH₂)₁₄CH₂Br from palmitic acid,

Question 44

When linoleic acid is hydrogenated, what organic compound is produced and how does its melting point compare to that of linoleic acid?

Question 45

When a vegetable oil is partially hydrogenated, how is its structure altered and how is its melting point affected?

Question 46

Provide the structure of the major organic compound that results when palmitic acid, CH₃(CH₂)₁₄CO₂H, is heated in methanol containing catalytic acid.

Question 47

What are the two major organic products which result when oleic acid,
is treated with ozone followed by dimethyl sulfide?

Question 48

How can the degree of unsaturation of an oil be gauged using a solution of bromine in carbon tetrachloride?

Question 49

How would you prepare CH₃(CH₂)₁₄CH₂NH₂ from palmitic acid,

Question 50

What reagents would you use to prepare octadecanal from stearic acid,

Question 51

Show the complete saponification of tristearin, including the reagents needed and the products of the reaction.

Question 52

If triolein (oleic acid: CH₃(CH₂)₇CH
CH(CH₂)₇COOH) was reacted with hydrogen in the presence of a transition metal catalyst, what would the new product be and how would the properties of the new compound be different from triolein?

Question 53

Provide the major organic product of the reaction shown below.

Question 54

Was the compound shown below more likely isolated from an animal or a plant? Explain.

Question 55

Draw the structure of the product which results when the compound shown below is completely hydrogenated using excess H₂.

Question 56

Provide the major organic product of the following reaction.

Question 57

Why do most fatty acids contain an even number of carbons?

Question 58

Draw the structure of a micelle and label which part is hydrophobic and which is hydrophilic.

Question 59

With which of the following reagents would linoleic acid not react?

A) HBr
B) Br₂
C) O₃
D) warm, concentrated KMnO₄
E) Na₂Cr₂O₇

Question 60

Using solely a fatty acid as your starting material, how would you synthesize a wax?

Question 61

Provide the major organic product of the following reaction.

Question 62

The sodium or potassium salt of a fatty acid is known as a ________.

Question 63

Which formula best characterizes hard-water scum?

A) [CH₃(CH₂)₁₆CO₂]₂Ca
B) CH₃CH₂CH=CHCH₂CH₂CH₂CO₂H
C) CH₃(CH₂)₁₆CO₂Na
D) CH₃(CH₂)₁₆CO₂H
E) CH₃(CH₂)₁₆SO₃Na

Question 64

Which of the following terms best describes the exterior surface of a soap micelle in water?

A) hydrophobic
B) hydrophilic
C) hard
D) saponified
E) hydrogenated

Question 65

Describe the intermolecular interaction of the surface carboxylate groups of a micelle and the surrounding water.

Question 66

Which of the following chemical reactions could be used to distinguish between a polyunsaturated vegetable oil and a petroleum oil containing a mixture of saturated and unsaturated hydrocarbons?

A) addition of bromine in carbon tetrachloride
B) ozonolysis
C) hydrogenation
D) lipidification
E) saponification

Question 67

Provide the major organic product of the following reaction sequence.

Question 68

Which of the following terms best describes the compound below?

A) a phospholipid
B) a cationic detergent
C) an alkaloid
D) a hard-water scum
E) a component of most lipid bilayers

Question 69

Provide the major organic product of the following reaction sequence.

Question 70

Which of the following terms best describes the interior of a soap micelle in water?

A) hydrophobic
B) hydrophilic
C) hard
D) saponified
E) hydrogenated

Question 71

Would the addition of HCl to the double bond of oleic acid,
occur with high regioselectivity? Explain.

Question 72

What organic compounds result when tristearin is heated in aqueous sodium hydroxide?

Question 73

Provide the structures of the major organic products which result when tristearin (shown below) is heated in aqueous solution of sodium hydroxide.

Question 74

What do we call a mixture of two immiscible liquids in which one liquid is dispersed throughout the other in small droplets?

Question 75

Which of the following terms best describes the compound below?
CH₃(CH₂)₄CH
CHCH₂CH
CH(CH₂)₇CO₂^-Na⁺

A) a wax
B) a soap
C) a terpene
D) a lecithin
E) a prostaglandin

Question 76

Given a single triglyceride which contains three identical and fully saturated fatty acid residues, which of the following terms accurately describe(s) it?

A) chiral
B) optically active
C) meso
D) optically inactive
E) both A and B

Question 77

________ is the base-promoted hydrolysis of fats and oils.

Question 78

Draw the two fatty acid structures that result from acid and base hydrolysis of a triacylglyceride and explain how they differ. (Use a core structure of 10 carbon atoms)

Question 79

Which of the following is an advantage of using an alkylbenzenesulfonate detergent over a common soap?

A) The alkylbenzenesulfonate detergent is uncharged.
B) The alkylbenzenesulfonate detergent has no hydrophobic region.
C) Greases are not emulsified by soaps.
D) Calcium, magnesium, and iron salts of sulfonic acids are soluble in water.
E) Sulfonates are protonated at higher pH's than are carboxylates.

Question 80

Arrange the following fatty acids in order of increasing melting point:
stearic acid, linolenic, linoleic, and oleic.