Which of the following changes occur due to denaturation of protein ? (A) Peptide bonds of the protein are readily available for hydrolysis (B) Solubility of protein increases (C) The viscosity decreases (D) Solubility of protein decreases (E) Biological properties such as catalytic, hormonal are lost Choose the correct answer from the options given below :
Protein Denaturation: Key Changes
Protein denaturation involves the disruption of the protein's native three-dimensional structure, primarily affecting secondary, tertiary, and quaternary structures, without breaking the peptide bonds that form the primary structure.
Consequences of Denaturation
Several changes occur upon denaturation:
- Increased Hydrolysis Accessibility: Denaturation unfolds the protein, exposing the internal peptide bonds. This makes them more readily available for hydrolysis reactions catalyzed by acids, bases, or enzymes. This corresponds to option (A).
- Decreased Solubility: As the protein unfolds, hydrophobic amino acid residues buried within the core become exposed to the solvent. These hydrophobic regions tend to associate with each other, leading to protein aggregation and a significant decrease in solubility. This corresponds to option (D).
- Loss of Biological Properties: The specific three-dimensional structure of a protein dictates its biological function, such as enzymatic activity or hormonal signaling. Denaturation destroys this precise structure, resulting in the loss of these specific biological properties. This corresponds to option (E).
Changes Not Typically Observed
Certain changes are contrary to what happens during denaturation:
- Solubility generally decreases, not increases (contrary to option B).
- Viscosity often increases due to unfolding and potential aggregation, rather than decreasing (contrary to option C).
Therefore, the changes observed due to denaturation are (A), (D), and (E).
Important Questions from Biochemistry
The following table lists names of scientists and advances made by them
Column A Column B A Linus Pauling (i) Myoglobin structure B Emil Fischer (ii) Model of α-helix C John Kendrew (iii) Lock and Key model D Christian Anfinsen (iv) Sequence-structure
Which one of the following options correctly matches contents of column A with column B?One gram of a polysaccharide composed of 1000 glucose units has the same effect on osmolarity as that of
Several proteins are modified by phosphorylation at specific amino acid residues to alter their activities. Which one of the following amino acids is NOT typically a site of phosphorylation in proteins?
The following statements are made with regard to the optical activity of amino acids derived from natural proteins:
A. All alpha-amino acids have the D stereochemical configuration.
B. All L-amino acids have the (S) absolute configuration except cysteine, which has the (R) absolute configuration.
C. All D-amino acids have the (S) absolute configuration except cysteine, which has the (R) stereochemical configuration.
D. In the absolute configuration system, L-threonine and L-isoleucine are (2S, 3R)-threonine and (2S, 3S)-isoleucine diastereomers, respectively.
Which one of the following options represents the combination of all correct statements?
How long should it take the polypeptide backbone of a 6-residue, 10-residue, 15-residue and 20-residue folding nucleus to explore all its possible conformations? Assume that the polypeptide backbone randomly reorients every 10-13 seconds (s).
