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Free download in PDF Protein Folding Objective Type Questions & Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(21)
Experiments on denaturation and renaturation after the reduction andreoxidation of the —S—S— bonds in the enzyme ribonuclease (RNase) have shown that:
[A]
folding of denatured RNase into the native, active conformation, requires the input of energy in the form of heat.
[B]
native ribonuclease does not have a unique secondary and tertiary structure.
[C]
the completely unfolded enzyme, with all —S—S— bonds broken, is still enzymatically active.
[D]
the primary sequence of RNase is sufficient to determine its specific secondary and tertiary structure.
Answer: the primary sequence of RNase is sufficient to determine its specific secondary and tertiary structure.
(22)
Which of the following is not known to be involved in the process of assisted folding of proteins?
[A]
Peptide bond hydrolysis
[B]
Heat shock proteins
[C]
Disulfide interchange
[D]
Chaperonins
Answer: Peptide bond hydrolysis
(23)
Protein S will fold into its native conformation only when protein Q is also present in the solution. However, protein Q can fold into its native conformation without protein S. Protein Q, therefore, may function as a ---------- for protein S.
[A]
ligand
[B]
molecular chaperone
[C]
protein precursor
[D]
structural motif
Answer: molecular chaperone
(24)
Which of the following statements concerning the process of spontaneous folding of proteins is false?
[A]
It may be an essentially random process.
[B]
It may be defective in some human diseases.
[C]
It may involve a gradually decreasing range of conformational species.
[D]
It may involve initial formation of a highly compact state.
Answer: It may be an essentially random process.
(25)
Chaperone proteins function by
[A]
providing a protective environment in which proteins can fold properly
[B]
degrading proteins that have folded improperly
[C]
providing a template for how the proteins should fold
[D]
rescuing proteins that folded incorrectly and allowing them to refold into proper configuration
Answer: rescuing proteins that folded incorrectly and allowing them to refold into proper configuration
(26)
Which of the following is least likely to result in protein denaturation?
[A]
Altering net charge by changing pH
[B]
Changing the salt concentration
[C]
Disruption of weak interactions by boiling
[D]
Exposure to detergents
Answer: Changing the salt concentration
(27)
An average protein will not be denatured by:
[A]
a detergent such as sodium dodecyl sulfate (SDS).
[B]
heating to 90°C.
[C]
iodoacetic acid.
[D]
pH 10.
(28)
PDI is an enzyme involve in
[A]
Protein synthesis
[B]
Protein degradation
[C]
Protein folding
[D]
Protein quaternery structure formation
(29)
Which of the following amino acids are rarely present in alpha helix
[A]
Glycine and proline
[B]
Proline and tryptophan
[C]
Tryptophan and glycine
[D]
Proline only
Answer: Glycine and proline
(30)
Αlpha-helix has
[A]
3.6 residues/turn and is a right handed helix
[B]
3.8 residues/turn and is a right handed helix
[C]
3.6 residues/turn and is a left handed helix
[D]
3.8 residues/turn and is a left handed helix
Answer: 3.6 residues/turn and is a right handed helix
31
All the statements regarding peptide bond are true except
[A]
Peptide bond is a co-valent bond
[B]
Peptide bond is rigid and planar
[C]
Peptide bond has partial double bond character
[D]
Peptide bond is formed by non-condensation reaction
Answer: Peptide bond is formed by non-condensation reaction
32
EF-1α and EF-Tu are
[A]
Analogs
[B]
Homologs
[C]
Paralogs
[D]
Syllogs