Question 1

Which of the following best describes the type of reaction that forms a peptide bond between two amino acids?

Accepted Answer

Condensation (dehydration) reaction

Question 2

A mutation changes a hydrophobic amino acid in the interior of a globular protein to a hydrophilic one. What is the most likely effect on the protein's tertiary structure?

Accepted Answer

The protein may misfold or become less stable due to disruption of hydrophobic core interactions.

Question 3

Which level of protein structure is directly determined by the sequence of amino acids?

Accepted Answer

Primary structure

Question 4

Which of the following bonds or interactions is most likely to be disrupted by a change in pH?

Accepted Answer

Ionic bonds

Question 5

Hemoglobin is an example of a protein with quaternary structure. Which statement best describes quaternary structure?

Accepted Answer

The association of multiple polypeptide subunits to form a functional protein

Question 6

Which of the following amino acids is most likely to form a disulfide bond?

Accepted Answer

Cysteine

Question 7

A protein is exposed to a reducing agent that breaks disulfide bonds. Which level(s) of protein structure could be affected?

Accepted Answer

Tertiary and quaternary structures

Question 8

Which of the following best explains why parallel and antiparallel β-sheets differ?

Accepted Answer

The directionality of the polypeptide chains is the same in parallel sheets and opposite in antiparallel sheets.

Question 9

Which of the following is a function of nucleic acids in cells?

Accepted Answer

Storing and transmitting genetic information

Question 10

Which of the following statements about the central dogma of molecular biology is correct?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 11

Which of the following best describes the bond that links nucleotides together in a nucleic acid polymer?

Accepted Answer

Phosphodiester bond

Question 12

Which of the following amino acids would most likely be found on the surface of a protein in an aqueous environment?

Accepted Answer

Glutamine

Question 13

A mutation causes a protein to lose its ability to bind DNA. Which domain is most likely affected?

Accepted Answer

DNA-binding domain

Question 14

Which of the following is a storage polysaccharide found in animals?

Accepted Answer

Glycogen

Question 15

Which of the following interactions is primarily responsible for the formation of α-helices and β-sheets in proteins?

Accepted Answer

Hydrogen bonds between backbone NH and CO groups

Question 16

Which of the following best explains why aspartate cannot form an ionic bond at low pH?

Accepted Answer

Its side chain is uncharged at low pH.

Question 17

Which of the following is true about protein domains?

Accepted Answer

Domains are discrete, locally folded units of tertiary structure with specific functions.

Question 18

Which of the following best describes the difference between fibrous and globular proteins?

Accepted Answer

Fibrous proteins have highly ordered, repetitive secondary structure, while globular proteins are folded into compact shapes.

Question 19

Which of the following is a correct statement about the directionality of protein and nucleic acid synthesis?

Accepted Answer

Proteins are synthesized from the N-terminus to the C-terminus; nucleic acids from 5' to 3'.

Chapter 3: Macromolecules – Proteins, Nucleic Acids, and Polysaccharides

Guida di studio - Domande di pratica

Study guide - Flashcard