Question 1

Which structural feature distinguishes saturated fatty acids from unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have only single bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 2

Why are saturated fats typically solid at room temperature, while unsaturated fats are liquid?

Accepted Answer

Saturated fats have straight hydrocarbon tails that pack tightly, while unsaturated fats have bent tails due to double bonds, preventing tight packing.

Question 3

Which of the following best describes the role of waxes in plants?

Accepted Answer

Waxes form a protective layer that restricts water loss and defends against pests.

Question 4

What is the main structural difference between triglycerides and phospholipids?

Accepted Answer

Phospholipids have two fatty acids and a phosphate group attached to glycerol, while triglycerides have three fatty acids attached to glycerol.

Question 5

Which of the following is a function of steroids in animal cells?

Accepted Answer

They serve as hormones that regulate reproductive system development.

Question 6

A fatty acid with the formula $\mathrm{C_{18}H_{36}O_2}$ is most likely:

Accepted Answer

A saturated fatty acid

Question 7

Which of the following statements about the solubility of fatty acids in water is correct?

Accepted Answer

Fatty acids are insoluble in water because their hydrocarbon tails are nonpolar.

Question 8

Which lipid type is characterized by a rigid backbone of four carbon rings?

Accepted Answer

Steroids

Question 9

What is the function of bile salts, which are derived from cholesterol?

Accepted Answer

They help digest fats in the digestive system.

Question 10

Which of the following best explains why unsaturated fatty acids are more flexible than saturated fatty acids?

Accepted Answer

Double bonds in unsaturated fatty acids create kinks in the hydrocarbon tail, increasing flexibility.

Question 11

Which of the following is NOT a function of lipids in living organisms?

Accepted Answer

Catalyzing chemical reactions

Question 12

A triglyceride molecule is formed by:

Accepted Answer

Three fatty acids bonded to a glycerol molecule

Question 13

Which of the following lipids is most likely to be found in honeycomb structures made by bees?

Accepted Answer

Waxes

Question 14

Which of the following best describes the amphipathic nature of phospholipids?

Accepted Answer

Phospholipids have both hydrophilic phosphate heads and hydrophobic fatty acid tails.

Question 15

Which of the following is a consequence of the presence of double bonds in unsaturated fatty acids?

Accepted Answer

The fatty acid tails become bent, preventing tight packing and resulting in a liquid state at room temperature.

Question 16

Which molecule is the most common steroid found in animal cell membranes?

Accepted Answer

Cholesterol

Question 17

Which of the following is true about the structure of waxes?

Accepted Answer

Waxes have long fatty acid tails bonded to long chain alcohols or carbon rings.

Question 18

Which of the following is a real-world example of a saturated fat?

Accepted Answer

Butter

Question 19

Which of the following best explains why phospholipids are essential for cell membrane structure?

Accepted Answer

Their hydrophobic tails and hydrophilic heads allow them to form bilayers that separate the cell from its environment.

Question 20

Which of the following is a function of vitamin D, a steroid derived from cholesterol?

Accepted Answer

It is needed by bones and teeth for proper development.

Lipids: Structure, Types, and Biological Functions

Study Guide - Practice Questions

Study Guide - Flashcards