Protein Engineering Questions and Answers for Freshers on “Bonds that Stabilize a Protein Molecule”.
1. Find the odd one out?
A. Hydrogen bond
B. Ionic bond
C. Hydrophobic interactions
D. Disulfide bond
Answer: D
Clarification: Hydrogen bond, Ionic bond, and hydrophobic interactions are types of non-covalent interactions. Disulfide bonds are a type of covalent interactions. Hence, the disulphide bond is the odd one out.
2. Which of the following options contain only non-covalent interactions?
A. Disulfide bond, Ionic bond
B. Ionic bond, peptide bond
C. Hydrogen bond, disulfide bond
D. Hydrogen bond, Ionic bond
Answer: D
Clarification: Hydrogen bond and Ionic bond are non-covalent interactions, whereas, disulfide bonds and peptide bonds are covalent interactions. Hence, among the options given the only option that contains only non-covalent interactions is hydrogen bond and Ionic bond.
3. Which of the following options contain only covalent interactions?
A. Disulfide bond, Ionic bond
B. Hydrogen bond, peptide bond
C. Hydrogen bond, Ionic bond
D. Disulfide bond, peptide bond
Answer: D
Clarification: Hydrogen bond and Ionic bond are non-covalent interactions. Disulfide bonds and peptide bonds are covalent interactions. Hence, among the options given the only option that contains only covalent interactions is disulfide bond, peptide bond.
4. Covalent interactions are generally weaker than non-covalent interactions.
A. True
B. False
Answer: B
Clarification: The above statement is false. Covalent interactions are always stronger than non-covalent interactions. Due to the sharing of electrons in covalent bonds, it is a strong bond. Examples of covalent interactions include disulfide bonds and peptide bonds.
5. Which among the following interactions is the weakest?
A. Disulfide bond
B. Peptide bond
C. Ionic bond
D. Hydrogen bond
Answer: D
Clarification: The bond energies are: disulfide bonds (251 kJ/mol), peptide bonds (80 kJ/mol), ionic bonds (42 kJ/mol), and hydrogen bonds (8-21 kJ/mol). Hence, among the given options hydrogen bond is the weakest bond.
6. Which among the following interactions is the weakest?
A. Ionic bond
B. Hydrogen bond
C. Hydrophobic interactions
D. Vander Waals interactions
Answer: D
Clarification: The bond energy of various bonds is as follows: hydrogen bonds (8-21 kJ/mol), ionic bonds (42 kJ/mol), Hydrophobic interactions (4-8 kJ/mol), Vander Waals interactions (4kJ/mol). Hence, among the given options Vander Waals interactions are the weakest interaction.
7. Vander Waals force arises from the attraction between transient dipoles generated by the rapid movement of electrons around the neutral atom.
A. False
B. True
Answer: B
Clarification: Vander Waals interactions are a type of non-covalent interactions. They are the weakest of the non-covalent interactions. Vander Waals force arises from the attraction between transient dipoles generated by the rapid movement of electrons around the neutral atom. Hence, the above statement is true.
8. Which of the following interactions involves charged groups?
A. Hydrophobic interactions
B. Disulfide bond
C. Hydrogen bond
D. Ionic bond
Answer: D
Clarification: Ionic bonds are a type of non-covalent interactions. Ionic interaction is due to the electrostatic interaction of two charged molecules. Hydrophobic interactions, disulfide bonds, and hydrogen bonds do not involve charged molecules. Hence, the ionic bond is the correct option.
9. The weak attractive forces of non-covalent interactions are not at all important for determining the properties and functions of biomolecules.
A. True
B. False
