$$\text{Triacylglycerol} + 3\text{NaOH} \xrightarrow{\text{heat}} 3\text{Sodium salts of fatty acids} + \text{Glycerol}$$

Question 1

Which of the following statements best describes the solubility properties of lipids?

Accepted Answer

Lipids are soluble in organic solvents but not in water because they are mostly nonpolar.

Question 2

Which structural feature distinguishes steroids from other classes of lipids?

Accepted Answer

A fused four-ring system consisting of three cyclohexane rings and one cyclopentane ring.

Question 3

A patient is advised to increase their intake of omega-3 fatty acids. Which food source would best meet this recommendation?

Accepted Answer

Cold-water fish

Question 4

Which of the following fatty acids is classified as polyunsaturated?

Accepted Answer

Linoleic acid

Question 5

What is the effect of cis double bonds in unsaturated fatty acids on their physical properties?

Accepted Answer

They decrease the melting point by causing kinks and reducing intermolecular interactions.

Question 6

Which reaction is responsible for the conversion of liquid vegetable oils into solid or semi-solid fats in the production of margarine?

Accepted Answer

Hydrogenation

Question 7

During digestion, triacylglycerols are hydrolyzed by lipase enzymes. What are the products of this reaction?

Accepted Answer

Glycerol and three fatty acids

Question 8

Which of the following is NOT a characteristic of lipids?

Accepted Answer

Soluble in water

Question 9

A triacylglycerol is formed from glycerol and three molecules of stearic acid. What is the name of this compound?

Accepted Answer

Glyceryl tristearate

Question 10

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

Accepted Answer

They must be obtained from the diet because the body cannot synthesize them.

Question 11

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

Accepted Answer

A glycerol backbone with two fatty acids, a phosphate group, and an amino alcohol

Question 12

What is the main function of sphingomyelin in the body?

Accepted Answer

Insulation and protection of nerve cells in the myelin sheath

Question 13

Which of the following reactions produces soap from triacylglycerols?

Accepted Answer

Saponification

Question 14

Which equation represents the saponification reaction of a triacylglycerol?

Accepted Answer

$$	ext{Triacylglycerol} + 3	ext{NaOH} \xrightarrow{	ext{heat}} 3	ext{Sodium salts of fatty acids} + 	ext{Glycerol}$$

Question 15

Which of the following is a function of prostaglandins in the body?

Accepted Answer

Regulation of blood pressure and inflammation

Question 16

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

Accepted Answer

Diffusion

Question 17

Which of the following statements about cholesterol is TRUE?

Accepted Answer

Cholesterol is needed for cell membranes, steroid hormones, and vitamin D.

Question 18

Which of the following lipoproteins is considered 'good' cholesterol and helps remove cholesterol from the bloodstream?

Accepted Answer

HDL

Question 19

Which structural feature is present in all fatty acids?

Accepted Answer

A long, unbranched carbon chain with a carboxylic acid group at one end

Question 20

Which of the following is a consequence of high levels of LDL in the blood?

Accepted Answer

Increased risk of atherosclerosis and heart disease due to plaque formation in arteries

Chapter 17: Lipids – Structure, Properties, and Biological Roles

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