Question 1

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

Accepted Answer

Three fatty acids attached to a glycerol backbone via ester bonds.

Question 2

Which type of lipid is primarily responsible for forming the bilayer structure of cell membranes?

Accepted Answer

Phospholipid

Question 3

A fatty acid contains the following structure: $ \mathrm{CH_3(CH_2)_{16}COOH} $. Is this fatty acid saturated or unsaturated?

Accepted Answer

Saturated

Question 4

Which of the following best explains why phospholipids are described as 'amphipathic'?

Accepted Answer

They contain both hydrophilic and hydrophobic regions.

Question 5

Compare the melting points of saturated and unsaturated fatty acids. Which statement is correct?

Accepted Answer

Saturated fatty acids have higher melting points due to straight chains that pack tightly.

Question 6

Which of the following is NOT a function of lipids in biological systems?

Accepted Answer

Catalyzing chemical reactions as enzymes

Question 7

A patient has a genetic disorder that prevents the synthesis of cholesterol. Which hormone would most likely be deficient?

Accepted Answer

Testosterone

Question 8

Which part of a phospholipid molecule interacts with water in the cell membrane?

Accepted Answer

The phosphate group (hydrophilic head)

Question 9

Which of the following best describes the difference between a phospholipid and a triglyceride?

Accepted Answer

Phospholipids have two fatty acids and a phosphate group; triglycerides have three fatty acids.

Question 10

Which of the following equations correctly represents the formation of a triglyceride from glycerol and fatty acids?

Accepted Answer

$ \mathrm{Glycerol + 3 \, Fatty \, Acids \rightarrow Triglyceride + 3 \, H_2O} $

Question 11

Which of the following statements about cholesterol in cell membranes is correct?

Accepted Answer

Cholesterol helps regulate membrane fluidity by preventing tight packing of phospholipids.

Question 12

Which of the following best describes the hydrophobic region of a phospholipid?

Accepted Answer

The fatty acid tails

Question 13

A cell membrane is described as a 'fluid mosaic.' Which component is responsible for the fluidity?

Accepted Answer

Unsaturated fatty acids in phospholipids

Question 14

Which of the following is a correct description of a lipid hormone?

Accepted Answer

A hormone derived from cholesterol that can pass through cell membranes.

Question 15

Which of the following is a structural function of cholesterol in animal cells?

Accepted Answer

Maintaining membrane stability and fluidity

Question 16

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

Accepted Answer

It has a hydrophilic hydroxyl group and a hydrophobic steroid ring structure.

Question 17

Which of the following is a difference between the structure of an unsaturated fatty acid and a saturated fatty acid?

Accepted Answer

Unsaturated fatty acids contain one or more double bonds; saturated fatty acids have only single bonds.

Question 18

Which of the following best explains why lipid bilayers form spontaneously in water?

Accepted Answer

Phospholipids arrange themselves so that hydrophilic heads face water and hydrophobic tails are shielded from water.

Question 19

Which of the following is a correct comparison of the functions of triglycerides and phospholipids?

Accepted Answer

Triglycerides store energy; phospholipids form cell membranes.

Lipids: Structure, Function, and Biological Importance (Chapter 34 Study Notes)

Study Guide - Practice Questions