Deck 31: Lipids

Question 1

How many isoprene units are in the following molecule?

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

Answer 1

4

Question 2

Which of the following sequences shows a reasonable series of 1,2-rearrangements as might be found in the biosynthesis of a steroid?

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

Answer 2

A

Question 3

How can an unsaturated fatty acid be converted into a saturated fatty acid?

A)Hydrogenation
B)Hydration
C)Ozonolysis
D)Hydrolysis

Answer 3

Hydrogenation

Question 4

What is (are) the basic subunits of terpenes?

A)Cyclohexane
B)Triacylglycerols
C)Isoprene
D)Carbonyls

Question 5

How many isoprene units are contained in the following molecule?

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

Question 6

What is the main cellular function of a triacylglycerol?

A)Signal transduction
B)Form cell membranes
C)Nerve cell transferal
D)Energy storage

Question 7

What happens to the melting point in fatty acids as the unsaturation increases?

A)It increases
B)It decreases.
C)There is no direct correlation between unsaturation and melting point.
D)The melting point stays the same.

Question 8

Eicosanoids are derived from what compound?

A)Arachidonic acid
B)Cyclohexane
C)Cholesterol
D)Triacylglycerols

Question 9

Provide a definition of the term lipid.

A)A compound with a carbonyl group
B)A compound with an aromatic ring
C)A hydrophobic biomolecule
D)A water-soluble compound

Question 10

Which of the following compounds is a steroid?

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

Question 11

Liquid oils usually have a higher percentage of what component compared to solid fats?

A)Oxygen
B)Hydrogen
C)Unsaturation
D)Aromatic rings

Question 12

Which of the following compounds is not a hydrolyzable lipid?

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

Question 13

What is (are) the biological precursor(s) for the formation of the steroid skeleton found in cholesterol?

A)Cyclohexane
B)Squalene
C)Triacylglycerols
D)Arachadonic acid

Question 14

Solid fats are generally from what source?

A)Vegetables
B)Starches
C)Legumes
D)Animals

Question 15

What chemical process causes an oil (such as soybean oil) to become rancid?

A)Hydrogenation with hydrogen
B)Hydration with water
C)Oxidation with molecular oxygen
D)Bromination with bromine

Question 16

Which structure represents the lowest energy conformation of a trans-decalin?

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

Question 17

What is the purpose of vitamin K?

A)Energy storage
B)Blood clotting
C)Photosynthesis
D)Hydrogenation

Question 18

Which of the following compounds is not a lipid?

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

Question 19

Which of the following is a phospholipid?

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

Question 20

What is the first key enzyme required for the synthesis of prostaglandins from arachidonic acid?

A)Protein Kinase C
B)Synthase
C)Transferase
D)COX (cyclic oxygenase)

Question 21

What is the name of the reaction of triglycerides with a base?

A)Esterification
B)Transesterification
C)Ozonolysis
D)Saponification

Question 22

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

A)Linoleic acid
B)Oleic acid
C)Arachidonic acid
D)Palmitoleic acid

Question 23

Sphingomyelins are a major component of the myelin sheath.Damage to the myelin sheath results in such diseases as multiple sclerosis.Which compound below corresponds to a sphingomyelin?

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

Question 24

From the statements below, pick out the one that is not correct for fat-soluble vitamins.

A)Fat-soluble vitamins are classified as lipids.
B)Fat-soluble vitamins are a group of biologically active compounds containing 20 carbon atoms.
C)Fat-soluble vitamins are required in small quantities for normal metabolism.
D)Fat-soluble vitamins are stored in fat cells for use when they are needed.

Question 25

What is the correct classification of the following compound? CH₃(CH₂)₁₅COOH

A)Saturated triglyceride
B)Simple lipid
C)Wax
D)Saturated fatty acid

Question 26

Which of the following are simple lipids?

A)Steroids
B)Terpenes
C)Waxes
D)Prostaglandins

Question 27

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

A)Palmitic acid
B)Arachidic acid
C)Stearic acid
D)Lauric acid

Question 28

Triacylglycerol A yields compound B when treated with excess H₂, Pd-C.Ozonolysis of A affords three molecules of compound C and one molecule of compound D.What is the structure of A?

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

Question 29

How many isoprene units can be found in the following compound?

A)1
B)4
C)8
D)9

Question 30

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

A)Linoleic acid
B)Oleic acid
C)Arachidonic acid
D)Palmitoleic acid

Question 31

Which of the following is not one of the three main categories of hydrolyzable lipids?

A)Waxes
B)Steroids
C)Triacylglycerols
D)Phospholipids

Question 32

Which of the following are complex lipids?

A)Steroids
B)Terpenes
C)Waxes
D)Protaglandins

Question 33

What is the structure of a cortisone derivative that has a C=C between C6 and C7, methyl group at C8 and chlorine at C12? The configuration of C8 is S and the configuration at C12 is R.

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

Question 34

The stereoselective introduction of the C15 OH group on the w side chain of prostaglandins has presented a challenge for synthetic chemists.Recently, Mulzer and co-workers demonstrated a new route in which the wside chain is synthesized independently and then attached to the bicyclic counterpart.What is the appropriate sequence of reagents for the following synthesis?

A)(1) PBr₃; (2) Grubbs' catalyst, Reagent X; (3) KOC(CH₃)₃
B)(1) PCC; (2) Ph₃P=CH₂; (3) Grubbs' catalyst, Reagent X
C)(1) PBr₃; (2) Ph₃P=CH₂; (3) Grubbs' catalyst, Reagent X
D)(1) TsCl, pyridine; (2) Grubbs' catalyst, Reagent X; (3) KOC(CH₃)₃

Question 35

Which of the following correctly describes waxes?

A)Long chain alcohols
B)Long chain esters
C)Long chain ethers
D)Long chain fatty acids

Question 36

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

A)Palmitic acid
B)Arachidic acid
C)Stearic acid
D)Lauric acid

Question 37

Which of the following classes of molecules is not a nonhydrolyzable lipid?

A)Steroids
B)Terpenes
C)Phospholipids
D)Eicosanoids

Question 38

What is the result of the oxidation of arachidonic acid with O₂ by cyclooxygenase?

A)It results in the synthesis of prostaglandins, thromboxanes, and prostacyclins.
B)It results in the synthesis of fat-soluble vitamins from sphingomyelins.
C)It results in the synthesis of phosphoacylglycerols.
D)It is an important step in the synthesis of lipids that form the lipid bilayer.

Question 39

Which of the following fatty acids is not present in natural fats and oils?

A)Hexadecanoic acid
B)Heptadecanoic acid
C)Octadecanoic acid
D)None of the choices