Question 1

Which of the following best describes the four major classes of biomacromolecules found in the human body?

Accepted Answer

Proteins, lipids, carbohydrates, nucleic acids

Question 2

Which class of biomolecules is primarily responsible for forming the structure of cellular membranes, as shown in the image of the bilayer?

Accepted Answer

Lipids

Question 3

Which of the following functional groups can act as hydrogen bond donors?

Select all that apply.

Accepted Answer

Amine group and amide group

Question 4

Which of the following statements about chiral carbons is correct?

Accepted Answer

A chiral carbon is bonded to four different groups or atoms.

Question 5

Which of the following is an example of a pair of enantiomers?

Accepted Answer

Two molecules that are non-superimposable mirror images

Question 6

Which class of amino acids has side chains that can form hydrogen bonds with water?

Accepted Answer

Neutral polar, acidic, and basic

Question 7

At physiological pH (pH 7.0), what is the charge state of the backbone functional groups of an amino acid?

Accepted Answer

The amine has a positive charge and the carboxylic acid has a negative charge

Question 8

Which of the following amino acids is considered shape-determining due to its unique side chain properties?

Accepted Answer

Proline

Question 9

Which of the following best describes a zwitterion?

Accepted Answer

A molecule with both a positive and a negative charge but overall neutral

Question 10

Which of the following bonds is formed between two amino acids during protein synthesis?

Accepted Answer

Peptide (amide) bond

Question 11

Which of the following interactions is primarily responsible for stabilizing the secondary structure of an $$b1-$$helix?

Accepted Answer

Hydrogen bonds forming between peptide bonds

Question 12

Which class of amino acids prefers to have their side chains in a hydrophobic environment?

Accepted Answer

Nonpolar

Question 13

Which of the following is a function of storage proteins in the body?

Accepted Answer

Store essential substances for immediate availability

Question 14

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

Accepted Answer

The sequence of amino acids linked by peptide bonds

Question 15

Which of the following interactions is most important for stabilizing quaternary protein structure?

Accepted Answer

Interactions between side chains of different polypeptide chains

Question 16

Which of the following amino acids can form disulfide bonds that stabilize protein tertiary or quaternary structure?

Accepted Answer

Cysteine

Question 17

Which of the following best explains why proteins fold into specific three-dimensional shapes?

Accepted Answer

To maximize hydrophobic interactions in the protein core and hydrophilic interactions on the surface

Question 18

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

Accepted Answer

$$\alpha-$$helices and $$\beta-$$sheets are stabilized by hydrogen bonds between backbone amide groups

Question 19

Which of the following statements about isoelectric point (pI) is correct?

Accepted Answer

At the isoelectric point, the amino acid has no net charge

Question 20

Which of the following best describes the role of enzymes in the body?

Accepted Answer

They catalyze biochemical reactions by lowering activation energy

Proteins and Their Amino Acid Building Blocks: Structure and Function

Study Guide - Practice Questions