Question 1

Which property of carbon is primarily responsible for the diversity of organic molecules found in living organisms?

Accepted Answer

Its ability to bond with four other atoms, allowing for complex structures

Question 2

Methamphetamine exists as two isomers: one is a powerful illegal drug, and the other is a sinus medication. What explains their different effects?

Accepted Answer

They have different structures, and molecular shape determines function

Question 3

Which of the following best describes a dehydration reaction in the formation of biological polymers?

Accepted Answer

A water molecule is removed to form a new bond between monomers

Question 4

A disaccharide is formed when two monosaccharides are joined by which type of reaction?

Accepted Answer

Dehydration reaction

Question 5

Which of the following is a correct general formula for a monosaccharide?

Accepted Answer

$$C_nH_{2n}O_n$$

Question 6

Cellulose and starch are both polysaccharides composed of glucose monomers. What is the primary difference in their biological roles?

Accepted Answer

Starch is used for energy storage in plants, while cellulose is structural in plant cell walls

Question 7

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

Accepted Answer

Unsaturated fatty acids have one or more double bonds, causing kinks in the chain

Question 8

Trans fats are produced by which process, and why are they considered a health risk?

Accepted Answer

By hydrogenating unsaturated fats; they are linked to increased heart disease risk

Question 9

Phospholipids are essential components of cell membranes because:

Accepted Answer

They have hydrophilic heads and hydrophobic tails, forming a bilayer

Question 10

Which of the following best explains why a denatured protein loses its function?

Accepted Answer

Its specific three-dimensional shape is lost

Question 11

A protein's tertiary structure is primarily determined by:

Accepted Answer

Interactions among R groups of amino acids

Question 12

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

Accepted Answer

Energy storage in adipose tissue

Question 13

The monomers that make up nucleic acids are called:

Accepted Answer

Nucleotides

Question 14

Which of the following best describes the structure of DNA?

Accepted Answer

A double helix composed of two polynucleotide chains

Question 15

Which of the following is a correct description of hydrolysis?

Accepted Answer

A reaction that adds a water molecule to break a bond between monomers

Question 16

A genetic mutation changes the primary structure of a protein. What is the most likely consequence?

Accepted Answer

The protein's secondary and tertiary structures may be altered, affecting its function

Question 17

Which of the following statements about lactose intolerance is correct?

Accepted Answer

It is caused by a lack of the enzyme lactase

Question 18

Which of the following best explains why sex hormones like testosterone and estradiol have different effects in the body?

Accepted Answer

They differ only in the functional groups attached to their carbon skeletons

Question 19

Which of the following is a real-world example of the importance of enzymes in biological systems?

Accepted Answer

Lactose intolerance due to the absence of lactase

Question 20

Which of the following best describes the evolutionary significance of lactose tolerance in some human populations?

Accepted Answer

It is due to different mutations in the DNA of several groups whose ancestors practiced dairy farming

The Molecules of Cells: Structure and Function of Biological Molecules

Study Guide - Practice Questions