Question 1

Which technique is commonly used to separate proteins based on their size, and what is the principle behind it?

Accepted Answer

SDS-PAGE, which uses sodium dodecyl sulfate to denature proteins and applies an electric field to separate them by size.

Question 2

In immunoblotting (Western blot), what is the main purpose of using antibodies?

Accepted Answer

To visualize specific proteins after they have been separated by SDS-PAGE.

Question 3

Which of the following is NOT a function of proteins in cells?

Accepted Answer

Storing genetic information.

Question 4

What is the primary structure of a protein?

Accepted Answer

The sequence of amino acids linked by peptide bonds.

Question 5

Which type of bond is responsible for stabilizing the secondary structure of proteins?

Accepted Answer

Hydrogen bonds

Question 6

A polypeptide is made up of 345 amino acids. If each amino acid is linked by a peptide bond, how many peptide bonds are present in this polypeptide?

Accepted Answer

$344$

Question 7

Which of the following statements about water is TRUE?

Accepted Answer

Water is polar and forms hydrogen bonds, which contribute to its unique properties.

Question 8

What is the main difference between DNA and RNA nucleotides?

Accepted Answer

DNA contains deoxyribose sugar while RNA contains ribose sugar.

Question 9

Which macromolecule is primarily responsible for storing genetic information?

Accepted Answer

Nucleic acids

Question 10

Which of the following is a function of small RNA molecules in gene regulation?

Accepted Answer

They bind to mRNA and inhibit its translation.

Question 11

What is the role of CRISPR in genome editing?

Accepted Answer

It introduces targeted changes in the DNA sequence.

Question 12

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

Accepted Answer

The arrangement and interaction of multiple polypeptide subunits.

Question 13

Which type of macromolecule is formed by the polymerization of monosaccharides?

Accepted Answer

Polysaccharides

Question 14

Which bond links two monosaccharides in a disaccharide?

Accepted Answer

Glycosidic bond

Question 15

Which of the following is a hydrophobic macromolecule important for cell membrane structure?

Accepted Answer

Lipid

Question 16

Which level of protein structure is directly affected by mutations that change the amino acid sequence?

Accepted Answer

Primary structure

Question 17

Which of the following is TRUE about the alpha-helix structure in proteins?

Accepted Answer

It is stabilized by hydrogen bonds between the backbone amide and carbonyl groups.

Question 18

Which of the following is a real-world application of blocking gene expression?

Accepted Answer

Treating genetic diseases by silencing mutant genes using RNA interference.

Question 19

Which of the following is a correct formula for the number of peptide bonds in a polypeptide with $n$ amino acids?

Accepted Answer

$n-1$

Question 20

Which of the following statements about prion diseases is correct?

Accepted Answer

Prion diseases are caused by misfolded proteins that induce misfolding in normal proteins.

Macromolecules of the Cell: Structure, Function, and Analysis

Study Guide - Practice Questions