Question 1

Which process is depicted in the first image, and what is its biological significance?

Accepted Answer

Dehydration synthesis; it is used to join smaller subunits into macromolecules, storing energy in the process.

Question 2

In the second image, what is the role of water in the depicted reaction?

Accepted Answer

Water is added to break bonds between subunits, releasing energy.

Question 3

Which type of macromolecule is being formed in the third image, and what are its components?

Accepted Answer

A triglyceride; composed of a glycerol and three fatty acids.

Question 4

The fourth image shows a lipid with straight hydrocarbon tails. What type of fat is this, and what is a key property?

Accepted Answer

Saturated fat; solid at room temperature.

Question 5

The fifth image shows a lipid with kinked hydrocarbon tails. What causes these kinks, and what is the biological consequence?

Accepted Answer

Double bonds between carbons; the fat is liquid at room temperature.

Question 6

The sixth image shows a molecule with a polar head and two nonpolar tails. What is this molecule, and what is its primary function in cells?

Accepted Answer

Phospholipid; forms the structural basis of cell membranes.

Question 7

Which of the following best describes the difference between dehydration synthesis and hydrolysis?

Accepted Answer

Dehydration synthesis removes water to form bonds; hydrolysis adds water to break bonds.

Question 8

A patient is unable to digest lactose due to a deficiency in the enzyme lactase. Which type of reaction is impaired in this patient?

Accepted Answer

Hydrolysis of lactose.

Question 9

Which of the following statements about phospholipids is correct?

Accepted Answer

They have a polar head and nonpolar tails, making them ideal for forming cell membranes.

Question 10

Which of the following best explains why saturated fats are solid at room temperature while unsaturated fats are liquid?

Accepted Answer

Saturated fats have straight tails that pack tightly; unsaturated fats have kinked tails that prevent tight packing.

Question 11

Which of the following is a correct example of a disaccharide and its monosaccharide components?

Accepted Answer

Lactose; glucose + galactose

Question 12

Which equation correctly represents the general formula for a monosaccharide?

Accepted Answer

$$C_nH_{2n}O_n$$

Question 13

Which of the following is a function of oligosaccharides in the human body?

Accepted Answer

Forming glycoproteins for cell recognition and communication.

Question 14

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

Accepted Answer

A backbone of three six-membered carbon rings and one five-membered carbon ring.

Question 15

Which polysaccharide is used for energy storage in animals, and what is its structure?

Accepted Answer

Glycogen; a highly branched polymer of glucose.

Question 16

Which of the following statements about the formation of macromolecules is correct?

Accepted Answer

Dehydration synthesis requires energy input and results in the storage of energy in chemical bonds.

Macromolecules: Structure, Formation, and Biological Roles

Study Guide - Practice Questions