Question

What do you understand by denaturation of proteins?

Answer 1

Hint: Denaturation of protein is an irreversible process. Once the structure of protein will be lost, it cannot be regained. Boiling of egg and curdling of milk are some examples of this process.

Complete answer:
-Denaturation of protein is a process in which protein or nucleic acid loses its structure, on application of certain stresses or compounds such as strong acids or bases, concentrated inorganic salts, etc. This can lead to some random polypeptide chains.
-This denaturation can cause disruption in the cell activity and may also lead to cell death.
- Denatured proteins show following characteristics such as
-conformational change.
- loss of solubility.
- aggregation due to exposure to hydrophobic groups.
- They will also lose their 3D structure.
- Protein must be folded in the right way in globular or membrane protein. Hydrogen bond plays a vital role in protein folding. The hydrogen bond being very weak, can easily get affected by heat, chemicals or other stressors. This leads to denaturation of proteins.
- Temperature and pH change can also cause this reaction.
- Uncoiling of the helix structure can also affect the biological activity.
Denaturation of protein in various protein structure are given below:
- In secondary structure, regular repeating patterns such as α-helix and β-pleated sheets are lost, and it will obtain a random coiled arrangement.
- In tertiary structure, denaturation causes disruption of covalent interactions between amino acid side chains and non-covalent dipole-dipole interactions between polar amino acid side chains.
- In quaternary structure, protein subunits are dissociated, and spatial arrangement of those subunits are disrupted.

Additional information:
Some examples of denaturation of protein are
- Boiling of egg
- Curdling of milk.

Note: - Denaturation of protein in the primary structure does not affect the sequence of amino acids held together by covalent bonds.
- Denaturation of protein is an irreversible process, but in some cases the denaturation process can be reversed. Such a process is called Renaturation.