Question 1

Which of the following best explains why proteins are considered highly diverse in both structure and function?

Accepted Answer

Proteins are made from 20 different amino acids with variable side chains, allowing for a wide range of shapes and functions.

Question 2

A protein is discovered that is shaped like a Y. This shape is primarily determined by which level(s) of protein structure?

Accepted Answer

The tertiary structure, but also influenced by primary and secondary structure

Question 3

Which part of an amino acid is responsible for its unique chemical properties?

Accepted Answer

The side chain (R group)

Question 4

During digestion in the small intestine, pancreatic enzymes break down proteins by which process, and what is the resulting product?

Accepted Answer

Hydrolysis; amino acids

Question 5

Which of the following statements about peptide bonds is correct?

Accepted Answer

Peptide bonds link the amino group of one amino acid to the carboxyl group of another, forming the backbone of a polypeptide.

Question 6

A mutation causes a single amino acid change in the hemoglobin protein, resulting in sickle cell anemia. This is an example of how changes in which level of protein structure can affect function?

Accepted Answer

Primary structure

Question 7

Which of the following amino acids would most likely be found on the surface of a protein that is dissolved in water?

Accepted Answer

Amino acids with polar or charged side chains

Question 8

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

Accepted Answer

Regular patterns such as α-helices and β-pleated sheets formed by hydrogen bonding between backbone atoms

Question 9

Which of the following interactions is NOT typically involved in stabilizing the tertiary structure of a protein?

Accepted Answer

Covalent bonds between peptide backbones

Question 10

A protein loses its tertiary and secondary structure after being exposed to high temperature. What is the most likely consequence?

Accepted Answer

The protein will lose its biological function due to denaturation.

Question 11

Which of the following is true about the directionality of a polypeptide chain?

Accepted Answer

The N-terminus contains a free amino group and is written on the left by convention.

Question 12

Which of the following is a correct statement about protein domains?

Accepted Answer

Domains are functional regions within a protein that may perform different parts of the protein's function.

Question 13

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

Accepted Answer

Storing genetic information

Question 14

Which of the following would most likely cause a protein to denature?

Accepted Answer

A change in pH or temperature

Question 15

Which of the following best describes a dehydration (condensation) reaction in the context of protein synthesis?

Accepted Answer

A reaction that links amino acids together by removing a water molecule

Question 16

Given the following amino acid side chain: $\mathrm{CH_2OH}$, which property would you expect it to have?

Accepted Answer

Polar and hydrophilic

Question 17

Which of the following is true about quaternary structure in proteins?

Accepted Answer

It arises when a protein consists of two or more polypeptide chains interacting.

Question 18

Which of the following types of bonds or interactions is most responsible for the formation of α-helices and β-pleated sheets in proteins?

Accepted Answer

Hydrogen bonds between backbone atoms

Question 19

A protein is found to be inactive and disordered until it is needed, at which point it folds into an ordered, active conformation. What does this illustrate about protein structure?

Accepted Answer

Protein shape is flexible and can be regulated by folding into active forms.

Question 20

Which of the following equations correctly represents the formation of a peptide bond between two amino acids?

Accepted Answer

$\mathrm{Amino\ acid_1} + \mathrm{Amino\ acid_2} \rightarrow \mathrm{Dipeptide} + \mathrm{H_2O}$

Organic Molecules: Proteins – Structure, Function, and Diversity

Study Guide - Practice Questions

Study Guide - Flashcards