Question 1

Which of the following best describes the relationship between a polypeptide and a protein?

Accepted Answer

A protein is composed of one or more polypeptides that perform a specific function.

Question 2

Which structural component of an amino acid is responsible for its unique chemical properties and interactions?

Accepted Answer

The R group (side chain)

Question 3

What type of chemical reaction forms a peptide bond between two amino acids?

Accepted Answer

Dehydration (condensation) reaction

Question 4

Which of the following environmental conditions is LEAST likely to cause protein denaturation?

Accepted Answer

Addition of a buffer at physiological pH

Question 5

A mutation causes a single amino acid substitution in the primary structure of a protein. Which level(s) of protein structure could be affected as a result?

Accepted Answer

Primary, secondary, tertiary, and quaternary structures

Question 6

Which of the following interactions is primarily responsible for maintaining the secondary structure of a protein?

Accepted Answer

Hydrogen bonds between backbone atoms

Question 7

Hemoglobin is an example of a protein with quaternary structure. What does this mean?

Accepted Answer

It has multiple polypeptide chains interacting to form a functional protein.

Question 8

Which of the following is TRUE regarding the N-terminus and C-terminus of a polypeptide?

Accepted Answer

The N-terminus contains a free amino group, and the C-terminus contains a free carboxyl group.

Question 9

Which of the following statements about protein folding is CORRECT?

Accepted Answer

Loss of proper folding results in loss of protein function.

Question 10

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

Accepted Answer

Storing genetic information

Question 11

A dipeptide is formed from two amino acids. What is the molecular formula for the water molecule released during this process?

Accepted Answer

$H_2O$

Question 12

Which of the following best explains why the order of amino acids in a polypeptide is important?

Accepted Answer

It determines the protein's final 3D structure and function.

Question 13

Which type of interaction is NOT involved in stabilizing the tertiary structure of a protein?

Accepted Answer

Hydrogen bonds between backbone atoms

Question 14

Which of the following statements about amino acids is FALSE?

Accepted Answer

The carboxyl group of one amino acid bonds to the R group of another during peptide bond formation.

Question 15

Which of the following best describes a peptide bond?

Accepted Answer

A covalent bond between the amino group of one amino acid and the carboxyl group of another

Question 16

Which protein is a 4-polypeptide globular protein that attaches to antigens and marks them for destruction?

Accepted Answer

IgG antibody

Question 17

Which of the following is a fibrous protein involved in muscle contraction regulation?

Accepted Answer

Tropomyosin

Question 18

Which of the following is TRUE about the nitrogen-carbon-carbon (N-C-C) backbone of a polypeptide?

Accepted Answer

It is formed by the repeated sequence of N-C-C atoms from each amino acid.

Question 19

Which of the following is a real-world example of a dipeptide with a specific biological function?

Accepted Answer

Kyotorphin, which plays a role in pain regulation in the brain

Proteins: Structure, Function, and Biological Importance

Study Guide - Practice Questions

Study Guide - Flashcards