Question 1

Which of the following statements best explains why carbon atoms are considered the most versatile building blocks of biological molecules?

Accepted Answer

Carbon atoms have a valence of 4, allowing them to form up to four covalent bonds with a variety of atoms.

Question 2

A dehydration synthesis (condensation reaction) between two monomers results in the formation of a polymer and the release of which molecule?

Accepted Answer

Water ($H_2O$)

Question 3

Which functional group is responsible for making a molecule act as an acid by donating a proton?

Accepted Answer

Carboxyl group ($-COOH$)

Question 4

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

Accepted Answer

Starch is a branched polymer of glucose, while cellulose is a linear, unbranched polymer of glucose.

Question 5

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

Accepted Answer

Storing genetic information

Question 6

A peptide bond is formed between which two functional groups of amino acids?

Accepted Answer

The carboxyl group of one amino acid and the amino group of another

Question 7

Which level of protein structure is primarily determined by the sequence of amino acids and is encoded by genes?

Accepted Answer

Primary structure

Question 8

Which of the following functional groups is critical for stabilizing protein structure through the formation of disulfide bridges?

Accepted Answer

Sulfhydryl group ($-SH$)

Question 9

Which macromolecule class includes molecules that are primarily hydrophobic and serve as long-term energy storage?

Accepted Answer

Lipids

Question 10

Which of the following statements about phospholipids is correct?

Accepted Answer

Phospholipids contain a hydrophobic tail and a hydrophilic head, making them ideal for forming cell membranes.

Question 11

Which of the following is a correct description of hydrolysis?

Accepted Answer

Hydrolysis is the breaking of a covalent bond between two monomers by the addition of water ($H_2O$).

Question 12

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

Accepted Answer

Most animals lack the enzyme required to hydrolyze the linkage in cellulose.

Question 13

Which of the following is a structural polysaccharide found in the exoskeleton of arthropods and the cell walls of fungi?

Accepted Answer

Chitin

Question 14

Which of the following is true about the secondary structure of proteins?

Accepted Answer

It is stabilized by hydrogen bonding between peptide linkages in the protein backbone.

Question 15

Which of the following is a correct statement about nucleic acids?

Accepted Answer

Nucleic acids are polymers of nucleotides linked together by dehydration synthesis.

Question 16

A molecule with the formula $C_6H_{12}O_6$ is most likely a:

Accepted Answer

Monosaccharide

Question 17

Which of the following functional groups is nonpolar and makes molecules hydrophobic?

Accepted Answer

Methyl group ($-CH_3$)

Question 18

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

Accepted Answer

Sucrose: glucose + fructose

Question 19

Which of the following statements about the tertiary structure of proteins is correct?

Accepted Answer

Tertiary structure is stabilized by interactions between side chains (R groups), including disulfide bridges and hydrogen bonds.

Question 20

Which of the following is a real-world application of dehydration synthesis in biological systems?

Accepted Answer

Formation of glycogen from glucose monomers in the liver

Biological Molecules: Structure, Function, and Classification

Study Guide - Practice Questions