Denaturation of Protein
All of the following are consequences of Protein denaturation EXCEPT:
| A | Loss of solubility | |
| B |
Loss of function |
|
| C | Loss of primary structure | |
| D |
Change in viscosity |
All of the following are consequences of Protein denaturation EXCEPT:
| A | Loss of solubility | |
| B |
Loss of function |
|
| C | Loss of primary structure | |
| D |
Change in viscosity |
Loss of primary structure REF: Lehninger Principles of Biochemistry, 4th Edition, page 147
“Protein denaturation leads to loss of Quaternary, Tertiary & Secondary functions, but the primary structure is preserved”
Denaturation is a phenomenon that involves transformation of a well-defined, folded structure of aprotein, formed underphysiological conditions, to an unfolded state under non-physiological conditions
Types of Denaturation: Temperature, Organic solvents, Surface, pH, Shear
Consequences of Denaturation:
- Loss of enzymatic activity/Function (death)
- Destruction of toxins
- Improved digestibility
- Loss of solubility
- Changes in texture
| A | Loss of solubility | |
| B |
Loss of function |
|
| C |
Loss of primary structure |
|
| D |
Change in viscosity |
Protein denaturation is defined as the partial or complete disorganization of a proteins characteristic three-dimensional shape as a result of disruption of its secondary, tertiary, and quaternary structural interactions.
Protein denaturation does not affect the primary structure of proteins.
Consequences of Denaturation:
- Loss of enzymatic activity/Function (death)
- Destruction of toxins
- Improved digestibility
- Loss of solubility
- Changes in texture
| A |
Unfolding occurs |
|
| B |
Disruption of the secondary structure occurs |
|
| C |
The sequence of amino acids remain the same |
|
| D |
Biological activity is retained |
Mild heating, treating with urea, salicylate, X-ray, ultraviolet rays, high pressure, vigorous shaking and similar Physico-chemical agents produce denaturation.
There will be non-specific alterations in secondary, tertiary and quaternary structures of protein molecules. The primary structure is not altered during denaturation.
In general, during the process, the solubility is decreased while the precipitability of the protein is increased. It often causes loss of biological activity.
True about denatured proteins ‑
| A |
Biologically inactive |
|
| B |
Soluble in water |
|
| C |
Primary structure of amino-acid sequence is disrupted |
|
| D |
Peptide bonds are hydrolysed |
Ans. ‘A’ Biologically inactive
Protein denaturation
The term denaturation refers to disruption of higher-order (secondary, tertiary and quaternary) structure of the proteinuria. All non-covalent bonds that maintain higher-order structure are disrupted, but peptide bond (covalent bond) remains intact.
- The primary structure is not altered during denaturation.
- Denaturation is always accompanied by a loss of biological function.
- Denatured proteins are less soluble and in many cases, they precipitate.
- Denaturation causing agents may be heat, detergents and organic solvents, strong acid and bases, 8M urea or 6 M guanidine chloride, heavy metal ions, trichloroacetic acid, and physical agents (X-rays, UV rays, high pressure).
