Protein Stability

Q1: Attractive Vander Waals forces occur between

A apolar molecules in the liquid state

B any pair of nearby atoms

C polar molecules in the solid state

D only if other forces are less favorable

ANS:B - any pair of nearby atoms

No answer description is available.

Q2: Unpaired H-bond donors and acceptors are found in the hydrophobic core of a protein

A only at the ends of a-helices

B only at the turns connecting p-strands

C only on Pro residues

D rarely

ANS:D - rarely

No answer description is available.

Q3: Buried hydrophobic side chains in a globular protein fit into a hole formed by the side chains of

A 1-3 other amino acids

B 5-7 other amino acids

C 9-12 other amino acids

D 13-15 other amino acids

ANS:B - 5-7 other amino acids

No answer description is available.

Q4: Which of the following forces is the most unfavorable for protein folding?

A Conformational entropy

B Hydrophobic interactions

C Vander Waals interactions

D Electrostatic interactions

ANS:A - Conformational entropy

Why conformation entropy? please explain.

Q5: At the midpoint of a temperature transition curve,

A half of the protein is denatured

B Keq = 1.0 and ΔG = 0

C [Native] = [Unfolded]

D All of these

ANS:D - All of these

No answer description is available.

Q6: For the unfolding reaction of Protein G, ΔH° =210.6 kJ/mol, this means that

A unfolding is favored enthalpically

B folding is favored enthalpically

C the entropy is positive at all temperatures

D the entropy is negative at all temperatures

ANS:B - folding is favored enthalpically

Please describe the given answer.

Q7: If the egg white protein, ovalbumin, is denatured in a hard-boiled egg, then which of the following is least affected?

A The primary structure of ovalbumin

B The secondary structure of ovalbumin

C The tertiary structure of ovalbumin

D The quaternary structure of ovalbumin

ANS:A - The primary structure of ovalbumin

No answer description is available.

Q8: Which of the following is the most correct?

A Charged amino acids are never buried in the interior of a protein

B Charged amino acids are seldom buried in the interior of a protein

C All hydrophobic amino acids are buried when a protein folds

D Tyrosine is only found in the interior of proteins

ANS:B - Charged amino acids are seldom buried in the interior of a protein

Answer should be D. How the answer is B. Can you explain it?

Q9: Since ΔG° = -RTlnK

A a 10-fold increase in K decreases ΔG° by about 10-fold

B a 10-fold decrease in K decreases ΔG° by about 2.3*RT

C a 10-fold increase in K decreases ΔG° by about 2.3*RT

D a 10-fold decrease in K increases ΔG° by about 10-fold

ANS:C - a 10-fold increase in K decreases ΔG° by about 2.3*RT

No answer description is available.

Q10: Which of the following forces is the most favorable for protein folding?

A Conformational entropy

B Hydrophobic Interactions

C Vander Waals interactions

D Hydrogen bonds

ANS:B - Hydrophobic Interactions

No answer description is available.

Q11: The correlation between free energy ΔG transfer between the aqueous/organic phases and the surface area of amino acid residues

A reflects the reduction in solvent-accessible area during protein folding

B is only meaningful for the polar amino acids

C ignores the important contribution of the peptide bond

D is similar to effects seen with SDS denaturation

ANS:A - reflects the reduction in solvent-accessible area during protein folding

No answer description is available.



img not found
img

For help Students Orientation
Mcqs Questions

One stop destination for examination, preparation, recruitment, and more. Specially designed online test to solve all your preparation worries. Go wherever you want to and practice whenever you want, using the online test platform.