Questions and answers for exam Preparation

MCQs

Total Questions : 63 | Page 2 of 7 pages

Question 11. Which of the following is untrue about Hydrophobicity?

The hydrophobic effect plays a dominant role in the folding of proteins
Hydrophobic residues aggregate away from contact with water
Hydrophobic residues aggregate to form hydrophobic cores with more polar residues
Hydrophobic residues form the solvent accessible surface but restrict the solubility of the protein

Discuss Question

Answer: Option D. -> Hydrophobic residues form the solvent accessible surface but restrict the solubility of the protein
Answer: (d).Hydrophobic residues form the solvent accessible surface but restrict the solubility of the protein

Question 12. Which of the following is untrue about Electrostatic Complementarity?

The electrostatic properties of biomolecules play an important role in determining interactions
The burial of charged residues at protein-protein/DNA interfaces is thought to be generally net destabilizing with the hydrophobic effect being the primary driving force
Charged groups involved in the biomolecular interface are often stabilized by other polar or oppositely charged groups on the interacting molecule
Charged groups involved in the biomolecular interface are often stabilized by similar polar or same charged groups on the interacting molecule

Discuss Question

Answer: Option D. -> Charged groups involved in the biomolecular interface are often stabilized by similar polar or same charged groups on the interacting molecule
Answer: (d).Charged groups involved in the biomolecular interface are often stabilized by similar polar or same charged groups on the interacting molecule

Question 13. Oligomers are often obligate complexes meaning that the free-energy cost of dissociation is high and they exist as oligomers under physiological conditions.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 14. Membership in a stable complex also differs from transient interaction in terms of evolutionary constraints upon sequence divergence.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 15. Which of the following is incorrect about Yeast-two-hybrid screens?

The yeast-two-hybrid system uses the transcription of a reporter gene driven by the Gal4 transcription factor to monitor whether or not two proteins are interacting
The DNA-binding domain chimeric protein will not bind upstream of the reporter gene
If the activation domain chimeric protein interacts with the DNA-binding domain chimeric protein, the reporter gene will be transcribed
Disadvantages of the method are that only pairwise interactions are tested, and not interactions that can only take place when multiple proteins come together, as well as a high false positive rate

Discuss Question

Answer: Option B. -> The DNA-binding domain chimeric protein will not bind upstream of the reporter gene
Answer: (b).The DNA-binding domain chimeric protein will not bind upstream of the reporter gene

Question 16. For proteins in stable complexes the average sequence identity is 46%, while for proteins in transient interactions it is 41%.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 17. Which of the following is incorrect about Purification of protein complexes followed by mass spectrometry?

Isolating protein complexes from cells allows identification of interactions between ensembles of proteins instead of just pairs
Systematic purification of complexes on a large scale is done by tagging hundreds of genes with an epitope
UnLike in the yeast-two-hybrid assay, this does not involve chimeric genes
Affinity purification based on the epitope will then extract all the proteins attached to the bait protein from cell lysates

Discuss Question

Answer: Option C. -> UnLike in the yeast-two-hybrid assay, this does not involve chimeric genes
Answer: (c).UnLike in the yeast-two-hybrid assay, this does not involve chimeric genes

Question 18. Which of the following is untrue?

Many entries in the Protein DataBank (PDB) are three-dimensional structures of multiple domains
The structures in PDB provide experimental information about interactions between domains at atomic detail
There are comparatively few three-dimensional structures compared to the amount of data available from the lower resolution large-scale experiments
Many entries in the Protein DataBank (PDB) are two-dimensional structures of multiple domains

Discuss Question

Answer: Option D. -> Many entries in the Protein DataBank (PDB) are two-dimensional structures of multiple domains
Answer: (d).Many entries in the Protein DataBank (PDB) are two-dimensional structures of multiple domains

Question 19. Which of the following is untrue about Amino acid conservation?

It has been known for some time that conservation of residues at the surface of a protein family is often related to function
Conservation of residues at the core of a protein family is often related to function
This may be an enzyme active-site or binding site
Unlike hydrophobicity or electrostatic potential, displaying residue conservation on the molecular surface has no physical or chemical basis

Discuss Question

Answer: Option B. -> Conservation of residues at the core of a protein family is often related to function
Answer: (b).Conservation of residues at the core of a protein family is often related to function

Question 20. The burial of surface area (or the maximization of surface contact) is an approximation of the effect of shape complementarity.