Question 1

Which functional groups are present in all standard amino acids?

Accepted Answer

A carboxyl group and an amino group

Question 2

What makes each standard amino acid unique?

Accepted Answer

The type of R group bonded to the α-carbon

Question 3

Which of the following is the correct 3-letter code for Tryptophan?

Accepted Answer

Trp

Question 4

Which 1-letter code is unique in that it is neither the first letter of the amino acid nor phonetic in origin?

Accepted Answer

K

Question 5

Which of the following amino acids is classified as nonpolar and hydrophobic?

Accepted Answer

Valine

Question 6

Which amino acid would have a net charge of +1 at physiological pH?

Accepted Answer

Lysine

Question 7

What type of interaction is most likely between alanine and isoleucine residues in a folded protein?

Accepted Answer

Hydrophobic interaction

Question 8

Which of the following amino acid pairs can form a salt bridge?

Accepted Answer

Lysine – glutamate

Question 9

Which of the following statements about primary protein structure is incorrect?

Accepted Answer

The peptide backbone can have non-amino acid parts in addition to amino acid residues.

Question 10

Which of the following statements represents a secondary structure for a protein?

Accepted Answer

The attractive force between the H atom of a peptide bond and the O atom of a peptide bond.

Question 11

What is the maximum number of turns for an alpha helix that contains 72 residues? (Assume 4 residues per turn)

Accepted Answer

18 turns

Question 12

Which of the following statements is true of β-sheets?

Accepted Answer

Their interior is characterized by hydrogen bonding between amide hydrogens and carbonyl oxygens.

Question 13

Which of the following statements about tertiary protein structure is incorrect?

Accepted Answer

The folding of a peptide into the tertiary structure destroys its secondary structure.

Question 14

Which one of the following interactions is most likely to be found at the surface of a folded peptide?

Accepted Answer

Hydrophilic interaction

Question 15

Which of the following correctly orders the protein structural terms from lowest to highest complexity?

Accepted Answer

Peptide Bond \u003c Primary structure \u003c Secondary structure \u003c Tertiary structure \u003c 2 subunits \u003c tetramer

Question 16

Which of the following would be an example of pH-based protein denaturation?

Accepted Answer

Adding lemon juice to milk.

Question 17

Which of the following statements about protein denaturation is true?

Accepted Answer

The amino acid sequence remains intact during and after denaturation.

Question 18

Which of the following amino acid pairs are most likely to form hydrogen bonds?

Accepted Answer

Serine – threonine

Question 19

Hemoglobin represents a commonly discussed tetramer that contains an even number of α and β subunits. Which of the following statements is true?

Accepted Answer

Hemoglobin must contain with 2 α subunits and 2 β subunits.

Amino Acids and Proteins: Structure, Classification, and Properties

Study Guide - Practice Questions