Question

Coagulation of egg, on heating is because of :

• A. Denaturation of protein occurs
• B. The secondary structure of protein remains unchanged
• C. Breaking of the peptide linkage in the primary structure of protein occurs
• D. Biological property of protein remains unchanged

Answer 1

The Correct Option is A

Coagulation of an egg upon heating is due to the denaturation of protein. Denaturation involves: - The disruption of the secondary, tertiary, and quaternary structures of the protein. - The breaking of weak bonds, such as hydrogen bonds and hydrophobic interactions, while leaving the primary structure (peptide bonds) intact.
Key Explanation: - Denaturation alters the protein’s native conformation, leading to coagulation (solidification). - The biological properties of the protein are lost due to denaturation.
Incorrect Options: (2) The secondary structure of the protein does not remain unchanged; it is disrupted during denaturation.
(3) The peptide bonds in the primary structure are not broken during coagulation.
(4) The biological properties of the protein do not remain unchanged; they are lost due to denaturation.
Final Answer: (1)

Answer 2

Step 1: Understanding the process.
An egg primarily contains proteins such as albumin, which are present in a colloidal form in the liquid state. When the egg is heated, these proteins undergo a change in their physical structure.

Step 2: Effect of heating on protein.
On heating, the weak hydrogen bonds and other secondary forces maintaining the native structure of the protein are broken. As a result, the protein loses its natural (globular) structure and unfolds into a more linear structure.

Step 3: Coagulation explanation.
The unfolded protein molecules then associate with one another through new intermolecular interactions, forming a solid network that causes the egg white to coagulate. This process is called denaturation of protein.

Step 4: Conclusion.
Thus, the coagulation of an egg on heating is due to the denaturation of proteins, where the protein structure changes irreversibly.

Final Answer: Denaturation of protein occurs