Deck 23: Biomolecules: Lipids and Their Metabolism

Question 1

Indicate by asterisks the stereogenic centers present in each of the indicated terpenes in the following question(s).
Place asterisks:
α-santonin

Answer 1

Question 2

Chemically, these are triacylglycerols, triesters of glycerol with three long-chain carboxylic acids.

A) waxes
B) fats and oils
C) fatty acids
D) soaps

Answer 2

fats and oils

Question 3

Draw the structure of the carbocation intermediate that results from the following step in terpene synthesis.

Answer 3

Question 4

Indicate by asterisks the stereogenic centers present in each of the indicated terpenes in the following question(s).
Place asterisks:
abietic acid

Question 5

Indicate by asterisks the stereogenic centers present in each of the indicated terpenes in the following question(s).
Place asterisks:
linalool

Question 6

How many constitutional isomers could be written for glyceryl monolaurate monomyristate monosterate?

Question 7

Draw the structure of calcium oleate. Would this substance be soluble or insoluble in water?

Question 8

In the sequence of steps shown below for fatty acid biosynthesis, how many cycles must be completed to produce the following species? Step
Type of Reaction
1
nucleophilic acyl substitution
2
nucleophilic acyl substitution
3
carboxylation
4
nucleophilic acyl substitution
5
condensation
6
reduction
7
dehydration
8
reduction

Question 9

Indicate by asterisks the stereogenic centers present in each of the indicated terpenes in the following question(s).
Place asterisks:
grandisol

Question 10

Draw the product of the following reaction, which is involved in the catabolism of triacylglycerols.

Question 11

Draw the structures of the major organic product(s) you would expect to obtain from reaction of androsterone with the reagents listed below. androsterone
Draw major product(s):
CH₃COCl, pyridine

Question 12

Draw the structure of glyceryl trimyristate and compare its melting point to that of glyceryl tristearate.

Question 13

Indicate by asterisks the stereogenic centers present in each of the indicated terpenes in the following question(s).
Place asterisks:
lineatin

Question 14

How many molecules of acetyl CoA are produced in the catabolism of stearic acid?

Question 15

Draw the structures of the major organic product(s) you would expect to obtain from reaction of androsterone with the reagents listed below. androsterone
Draw major product(s):
POCl₃, pyridine

Question 16

Which of the following would be expected to be found in higher concentration in butter versus olive oil?

A) CH₃(CH₂)₁₂CO₂H
B) CH₃(CH₂)₇CHCH(CH₂)₇CO₂H
C) CH₃(CH₂)₄(CHCHCH₂)₂(CH₂)₆CO₂H
D) CH₃(CH₂)₄(CHCHCH₂)₄(CH₂)₂CO₂H

Question 17

Write the saponification reaction of glyceryl distearate monooleate.

Question 18

The following sequence represents the steps in the biosynthesis of fatty acids.
Step
Type of Reaction
1
nucleophilic acyl substitution
2
nucleophilic acyl substitution
3
carboxylation
4
nucleophilic acyl substitution
5
condensation
6
reduction
7
dehydration
8
reduction
a)In which step is the new carbon−carbon bond that builds the fatty acid chain formed?
b)In which step does the following reaction occur? c)
Complete the reaction below by giving the species that should be placed in each box. d)
In which step is the mechanism identical to the conversion of pyruvate to oxaloacetate in gluconeogenesis?
e)
In what respect are steps 1 and 2 identical to steps 3 and 4?
f)
In which step is the butyryl group formed?

Question 19

How many passages through the β-oxidation pathway are required to completely degrade the following fatty acid?
CH₃(CH₂)₁₂CO₂H

Question 20

Draw the structures of the major organic product(s) you would expect to obtain from reaction of androsterone with the reagents listed below. androsterone
Draw major product(s):
NaBH₄, ethanol

Question 21

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
A triglyceride

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 22

Which of the following would function in a regulatory capacity?

A) aldosterone
B) androsterone
C) norethindrone
D) estradiol

Question 23

Cell membranes, which form an effective barrier to the passage of ions and other components into and out of the cell, are:

A) fatty acid esters
B) tricacylglycerols
C) lipid bilayers
D) micelles

Question 24

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
A sphingolipid

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 25

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
A phosphoglyceride

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 26

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
Monoterpene precursor

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 27

When soaps disperse in water, the long hydrocarbon tails cluster together in a hydrophobic ball, while the ionic heads on the surface of the cluster stick out into the water. These spherical clusters are called:

A) fatty acid esters
B) triacylglycerols
C) lipid bilayers
D) micelles

Question 28

The major lipid components of cell membranes are:

A) sphingolipids
B) fatty acids
C) phosphoglycerides
D) terpenoids

Question 29

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
Starting material for fatty acid biosynthesis.

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 30

Which of the following processes is used to harden an oil to give a fat?

A) oxidation
B) hydrogenation
C) hydrolysis
D) hydration

Question 31

Which of the following represents a similarity between the β-oxidation pathway and the biosynthesis of fatty acids?

A) identity of the acyl group carriers
B) stereochemistry of reaction intermediates
C) identity of the redox coenzymes
D) involvement of acetyl CoA
E) all of these are similarities

Question 32

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

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

Question 33

Which of the following is not true about cholesterol?

A) a steroid
B) a precursor for other steroids
C) produced from lanosterol
D) geometry allows for ring-flips
E) all of these are true

Question 34

Progesterone and progestin are examples of:

A) androgens
B) estrogens
C) progestins
D) glucocorticoids

Question 35

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

A) lauric acid
B) oleic acid
C) linoleic acid
D) linolenic acid

Question 36

The source of oxygen for β-oxidation is:

A) CO₂
B) O₂
C) Peroxide
D) Water
E) None of these is the source of oxygen for β-oxidation.

Question 37

All of the following describe β-oxidation, except:

A) Two-carbon units are eliminated during each cycle.
B) The process employs NAD⁺ as an oxidant.
C) The process is the primary route to fatty acid degradation.
D) The 2-carbon groups are eliminated from the methyl end of the fatty acid.
E) Fatty acids are attached to coenzyme A during the process.

Question 38

All of the following are byproducts of β-oxidation, except:

A) Acetyl CoA
B) ADP
C) NADH
D) FADH₂
E) All of these are byproducts of β-oxidation.

Question 39

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
An estrogen

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 40

The β-oxidation of odd-numbered fatty acids is characterized by direct formation of:

A) Acetyl CoA.
B) Methylmalonyl CoA.
C) Propionyl CoA
D) Succinyl CoA
E) There are no characteristic products in this process.

Question 41

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
A terpenoid

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)

Question 42

Match each of the given terms to a structure from the list below. There is only one correct structure for each term, and structures may be used more than once.
A soap

A)
B)
C)
D)
E)
F)
G)Malonyl ACP
H)
I)
J)