Question 1

Which of the following statements best explains why carbon is the backbone of biological macromolecules?

Accepted Answer

Carbon can form up to four covalent bonds, allowing for a variety of stable and complex structures.

Question 2

Which of the following is NOT a true polymer?

Accepted Answer

Lipid

Question 3

A dehydration reaction is used to:

Accepted Answer

Synthesize polymers by removing a water molecule and forming a covalent bond.

Question 4

Which of the following best describes the difference between starch and cellulose?

Accepted Answer

Starch has α-1,4 glycosidic linkages, while cellulose has β-1,4 glycosidic linkages.

Question 5

Which functional group is responsible for the acidic properties of amino acids?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 6

A molecule with the formula $$C_5H_{12}$$ can have different structures. These are called:

Accepted Answer

Isomers

Question 7

Which of the following best explains why trans fats are considered unhealthy?

Accepted Answer

They have trans double bonds, which can increase LDL cholesterol and risk of heart disease.

Question 8

Which of the following is a correct pairing of a macromolecule and its monomer?

Accepted Answer

Carbohydrate – Monosaccharide

Question 9

Which of the following best describes the tertiary structure of a protein?

Accepted Answer

The overall three-dimensional shape of a polypeptide resulting from interactions among R groups.

Question 10

A single amino acid substitution in the hemoglobin protein causes sickle-cell disease. This is an example of:

Accepted Answer

A change in the primary structure that affects protein function.

Question 11

Which of the following statements about DNA and RNA is correct?

Accepted Answer

DNA is usually double-stranded, while RNA is usually single-stranded.

Question 12

Which of the following best describes the role of ATP in the cell?

Accepted Answer

ATP stores potential energy that can be released by hydrolysis to power cellular work.

Question 13

Which of the following is a function of phospholipids in biological systems?

Accepted Answer

Forming the main structural component of cell membranes

Question 14

Which of the following best explains why cellulose cannot be digested by most animals?

Accepted Answer

Most animals lack the enzyme to hydrolyze β-1,4 glycosidic linkages in cellulose.

Question 15

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

Accepted Answer

Steroids have a carbon skeleton consisting of four fused rings.

Question 16

Which of the following best describes the difference between cis and trans isomers?

Accepted Answer

Cis isomers have functional groups on the same side of a double bond, while trans isomers have them on opposite sides.

Question 17

Which of the following is a correct description of a hydrolysis reaction?

Accepted Answer

A reaction that adds water to break a bond in a polymer.

Question 18

Which of the following best explains why fats are a more efficient energy storage molecule than carbohydrates?

Accepted Answer

Fats contain more energy-rich C-H bonds per gram than carbohydrates.

Question 19

Which of the following is a correct pairing of a nitrogenous base with its complementary base in DNA?

Accepted Answer

Adenine – Thymine

Question 20

Which of the following best describes the role of chitin in living organisms?

Accepted Answer

Chitin is a structural polysaccharide in arthropod exoskeletons and fungal cell walls.

Chapter 3: Carbon and the Molecular Diversity of Life – Study Notes

Study Guide - Practice Questions