Question 1

Which of the following statements best explains why lipids are not soluble in water?

Accepted Answer

Lipids are mostly nonpolar molecules with long hydrocarbon chains.

Question 2

Which structural feature distinguishes steroids from other classes of lipids?

Accepted Answer

Presence of a fused four-ring system

Question 3

A fatty acid with the formula $$CH_3$$-($$CH_2$$)_{14}-COOH$$ is classified as:

Accepted Answer

Saturated

Question 4

Which of the following is NOT a characteristic of lipids?

Accepted Answer

Soluble in water

Question 5

Oleic acid has the condensed structural formula $$CH_3$$-($$CH_2)_7-CH=CH$$-($$CH_2)_7-$$COOH$$. Which of the following is true about oleic acid?

Accepted Answer

It is a monounsaturated fatty acid.

Question 6

Which process converts the double bonds in unsaturated fatty acids to single bonds, resulting in a more solid fat?

Accepted Answer

Hydrogenation

Question 7

During saponification, what are the products when a triacylglycerol reacts with NaOH?

Accepted Answer

Glycerol and sodium salts of fatty acids (soap)

Question 8

Which of the following fatty acids must be obtained from the diet because humans cannot synthesize it?

Accepted Answer

Linoleic acid

Question 9

Which of the following statements about the melting points of fats and oils is correct?

Accepted Answer

Fats have higher melting points than oils because they contain more saturated fatty acids.

Question 10

Which of the following is a function of omega-3 fatty acids in the body?

Accepted Answer

Lower the possibility of blood clots by reducing platelet aggregation

Question 11

Which of the following reactions is catalyzed by the enzyme lipase during digestion?

Accepted Answer

Triacylglycerol $$+ 3H_2O$$ \rightarrow$$ Glycerol $$+$ 3 Fatty acids

Question 12

Which of the following best describes the structure of a glycerophospholipid?

Accepted Answer

Glycerol backbone, two fatty acids, phosphate group, and amino alcohol

Question 13

Which of the following is true about the lipid bilayer in cell membranes?

Accepted Answer

The nonpolar tails are oriented toward the center of the bilayer, away from water.

Question 14

Which type of transport moves particles across a cell membrane from a high concentration to a low concentration without the use of energy?

Accepted Answer

Diffusion (passive transport)

Question 15

Which of the following is a correct product of the complete hydrogenation of glyceryl trioleate?

Accepted Answer

Glyceryl tristearate

Question 16

Which of the following statements about trans fatty acids is correct?

Accepted Answer

Trans fatty acids behave like saturated fatty acids in the body.

Question 17

Which of the following is a function of cholesterol in the cell membrane?

Accepted Answer

Adds strength and rigidity to the membrane

Question 18

Which of the following is NOT a component of a sphingomyelin molecule?

Accepted Answer

Glycerol backbone

Question 19

Which of the following lipoproteins is responsible for transporting cholesterol from tissues to the liver for elimination?

Accepted Answer

High-density lipoprotein (HDL)

Chapter 15: Lipids – Structure, Types, and Properties

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