Question 1

Which of the following best describes the general property of lipids?

Accepted Answer

They are hydrophobic and not soluble in water.

Question 2

Which structural feature is common to all fatty acids?

Accepted Answer

A long hydrocarbon chain with a carboxylic acid group at one end.

Question 3

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

Accepted Answer

They have only single C–C bonds and tend to be solid at room temperature.

Question 4

A fatty acid with the structure $$\mathrm{CH_3$(CH_2$)7CH=CH(CH_2$)_7COOH} is $$best classified as:

Accepted Answer

A monounsaturated fatty acid.

Question 5

Which of the following is NOT a characteristic of lipids?

Accepted Answer

Soluble in water.

Question 6

Which of the following best explains why unsaturated fatty acids have lower melting points than saturated fatty acids?

Accepted Answer

The double bonds in unsaturated fatty acids create kinks, preventing tight packing.

Question 7

Which of the following is an essential fatty acid for humans?

Accepted Answer

Linoleic acid

Question 8

Which of the following best describes the function of HDL (high-density lipoprotein) in the body?

Accepted Answer

Helps remove cholesterol from the blood and transport it to the liver for excretion.

Question 9

A triacylglycerol is formed by the reaction of:

Accepted Answer

Three fatty acids and one glycerol molecule.

Question 10

Which of the following statements about waxes is correct?

Accepted Answer

Waxes are esters formed from long-chain fatty acids and long-chain alcohols.

Question 11

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

Accepted Answer

A molecule containing four fused carbon rings.

Question 12

Prostaglandins are best described as:

Accepted Answer

Local chemical messengers derived from fatty acids that regulate inflammation and smooth muscle contraction.

Question 13

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen reduce pain and inflammation by:

Accepted Answer

Blocking the synthesis of prostaglandins.

Question 14

Which of the following fatty acids is most likely to be a solid at room temperature?

Accepted Answer

Stearic acid (saturated)

Question 15

Which of the following best describes an omega-3 fatty acid?

Accepted Answer

A fatty acid with a double bond at the third carbon from the methyl (omega) end.

Question 16

Which of the following is a correct condensed structural formula for a saturated fatty acid?

Accepted Answer

$$\mathrm{CH_3$(CH_2$)_{16}COOH}$$

Question 17

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 18

Which of the following best explains why omega-3 fatty acids are considered beneficial for cardiovascular health?

Accepted Answer

They lower the tendency of blood platelets to stick together, reducing the risk of blood clots.

Question 19

A triacylglycerol molecule contains:

Accepted Answer

One glycerol molecule and three fatty acids.

Question 20

Which of the following is a correct description of the function of waxes in nature?

Accepted Answer

They provide waterproof coatings for leaves and animal fur.

Chapter 15: Lipids – Structure, Types, and Biological Roles

Study Guide - Practice Questions