Deck 8: Lipids

Question 1

In most cases, glycerol phosphatides have ____ fatty acid at position 1 and ____ fatty acid at position 2 of the glycerol.

A) a saturated; a saturated
B) a saturated; an unsaturated
C) an unsaturated; a saturated
D) an unsaturated; an unsaturated
E) none are true.

Answer 1

B

Question 2

Of the following fatty acids, which would have physical and physiological properties most similar to elaidic acid, pictured below?

A) oleic acid (18:1Δ⁹)
B) lauric acid (12:0)
C) linoleic acid (18:2Δ^9,12)
D) stearic acid (18:0)
E) arachidonic acid (20:4Δ^5,8,11,14)

Answer 2

D

Question 3

Lipids are the biomolecules of choice for storage of metabolic energy because they:

A) are soluble in water.
B) yield a large amount of energy upon oxidation.
C) are highly oxidized.
D) are easily hydrolyzed.
E) are amphipathic.

Answer 3

B

Question 4

The structure is an example of a(n):

A) diacylglycerol.
B) triacylglycerol.
C) wax ester.
D) eicosanoid.
E) monoacylglycerol.

Question 5

Body fat is a major storage form of energy because it:

A) aggregates in a highly anhydrous form (without additional water weight).
B) yields about 17 kJ/g (4 cal/g) of energy.
C) has low insulation properties.
D) is highly hydrated and easy to metabolize.
E) yields about 25 kJ/g (6 cal/g) of energy.

Question 6

Diets aimed at reducing coronary heart disease should be:

A) low in trans-fatty acids and high in saturated fatty acids.
B) high in trans-fatty acids and high in saturated fatty acids.
C) high in trans-fatty acids and low in saturated fatty acids.
D) low in trans-fatty acids and low in saturated fatty acids.
E) low in trans-fatty acids and low in unsaturated fatty acids.

Question 7

The terpenes are all EXCEPT:

A) made up of isoprene monomers.
B) formed from two or more 2-methyl-1,3-butadiene molecules.
C) components of wool wax.
D) monomers units linked head to tail.
E) all are true.

Question 8

Platelet activating factor (PAF) has all of the characteristics EXCEPT:

A) PAF is a potential mediator in inflammation, allergic responses and shock.
B) PAF is a sphingolipid.
C) PAF has a beneficial effect on toxic-shock syndrome.
D) PAF is involved in implantation of the egg in the uterine wall.
E) PAF stimulates production of fetal lung surfactant.

Question 9

All of the following are terpenes EXCEPT:

A) squalene.
B) α-tocopherol (vitamin E).
C) coenzyme Q (UQ).
D) limonene.
E) cetyl palmitate (spermaceti).

Question 10

Fatty acids are all EXCEPT:

A) either saturated or unsaturated.
B) found seldom in free form.
C) mostly found with an even number of carbons.
D) found in linear, branched and cyclic forms.
E) all are true.

Question 11

Dietary essential fatty acids for humans include

A) γ-linolenic and oleic acids.
B) oleic and linoleic acids.
C) palmitic and oleic acids.
D) linoleic and γ-linolenic acids.
E) all are true.

Question 12

Alkali hydrolysis of triacylglycerols is called ____ and yields ____ and ____.

A) triacylation; fatty acids; glycerol
B) saponification; fatty alcohols; fatty acids
C) triesteration; salts of fatty acids, fatty alcohols
D) saponification; salts of fatty acids; glycerol
E) none are true

Question 13

Which of the following alcohols is correctly paired with the functional group that it contains?

A) ethanolamine: secondary amine group
B) choline: quaternary ammonium group
C) inositol: aldehyde and alcohol groups
D) glycerol: ether
E) none of the above are correct

Question 14

Certain phospholipids, including ____ and ____, participate in complex cellular signaling events.

A) phosphatidylcholine; phosphatidylserine
B) phosphatidylserine; phosphatidylalanine
C) phosphatidylcholine; phosphatidylglycerol
D) phosphatidylinositol; phosphatidylcholine
E) phosphatidylethanolamine; phosphatidylserine

Question 15

A fatty acid with eighteen carbons and one double bond could be designated all EXCEPT:

A) linoleic acid.
B) 18:1.
C) cis-9-octadecenoic acid.
D) oleic acid.
E) elaidic acid

Question 16

Glycerolphospholipids are all EXCEPT:

A) also called sphingolipids.
B) essential components of cell membranes.
C) made up of 1,2-diacylglycerol and a phosphate group.
D) members of the phospholipids.
E) all are true.

Question 17

Of the following, which would contain the largest amount of fatty acids with trans double bonds?

A) the fatty acid on carbon #1 of the glycerol of phosphatidylcholine
B) butter
C) canola oil
D) the 2 lb, 99 cent package of cookies containing partially hydrogenated cottonseed and/or soybean oil that you consumed with 3 (or more) cups of coffee while studying last night (or early this morning)
E) none of the above would have very much trans-double bond containing fatty acids

Question 18

Although present in small amounts in most membranes, glycosphingolipids have a number of cellular functions EXCEPT:

A) involvement in nerve impulse transmission.
B) water-repellant properties of animal skin.
C) tissue and organ specificity.
D) cell-cell recognition.
E) tissue immunity.

Question 19

Glycosphingolipids consist of a ____ with one or more ____ residues in a(n) ____ linkage at the 1-hydroxyl moiety.

A) sugar; fatty acids; ester
B) ceramide; sugar; β-glycosidic
C) ceramide; fatty acid; amide
D) glycerol; fatty acids; ester
E) none are true

Question 20

Membranes with unsaturated fatty acids in their components are more flexible and fluid because:

A) Unsaturated fatty acids pack closely together to form ordered arrays.
B) Unsaturated fatty acids bend at the double bond preventing close packing.
C) Saturated fatty acids have a "kink" that produces more fluid aggregates.
D) Unsaturated fatty acids have cis double bonds that prevent formation of the "kink."
E) All of the above are correct.

Question 21

Briefly explain waxes.​

Question 22

Cholesterol is a component of all EXCEPT:

A) lipoproteins.
B) plant cell plasma membranes.
C) membranes of intracellular organelles.
D) animal cell membranes.
E) all are true.

Question 23

Discuss the metabolites of sphingolipids and their effects.​

Question 24

Which of the following best describes the following molecule?

A) a monoterpene with a tail-to-tail linkage
B) a monoterpene with a head-to-tail linkage
C) a diterpene with a tail-to-tail linkage
D) a diterpene with a head-to-tail linkage
E) none of the above

Question 25

Which of the following bonds would be cleaved by phospholipase C?

A) 1
B) 2
C) 3
D) 4
E) none of the above

Question 26

Discuss ether glycerophospholipids.​

Question 27

The steroid hormones that participate in the control of carbohydrate, protein and lipid metabolism are the:

A) progestins.
B) mineralocorticoids.
C) estrogens.
D) glucocorticoids.
E) androgens.

Question 28

Which of the following enzymes is responsible for the release of arachidonic acid from membrane phospholipids?

A) phospholipase A₁
B) phospholipase A₂
C) phospholipase B
D) phospholipase C
E) phospholipase D

Question 29

Plant sterols are:

A) so similar to cholesterol that they undergo the same physiology and metabolism.
B) different isomers of cholesterol at the double bond location only.
C) to be avoided in your diet because they elevate blood cholesterol levels.
D) highly effective in blocking the absorption of cholesterol by intestinal cells.
E) none are true.

Question 30

All are plant steroids EXCEPT:

A) campesterol.
B) stigmasterol.
C) β-sitosterol.
D) cortisol.
E) all are true.

Question 31

Which of the following steroid hormones is NOT correctly defined?

A) testosterone: an androgen involved in male sexual development
B) progesterone: a progestin that controls the menstrual cycle.
C) cortisol: a glucocorticoid that controls nutrient metabolism
D) estradiol: a progestin involved in female sexual development
E) all are correctly defined

Question 32

The reaction below is catalyzed by:

A) desmolase.
B) 17α-hydroxylase.
C) 17,20-lyase.
D) 17β-hydroxysteroid dehydrogenase.
E) none of the above are true.

Question 33

Which of the following would be considered an ω-3 fatty acid?

A) linoleic acid: 9,12-octadecadieneoic acid (18:2Δ^9,12)
B) eicosapentaenoic acid: 5,8,11,14,17-eicosapentaenoic acid (20:5Δ^5,8,11,14,17)
C) γ-linolenic acid: 6,9,12-octadecatrieneoic acid (18:3Δ^6,9,12)
D) arachidonic acid: 5,8,11,14-eicosatetraenoic acid (20:4Δ^5,8,11,14)
E) none of the above

Question 34

Discuss the different steroid hormones derived from cholesterol.​

Question 35

Discuss the biological significance of terpenes.​