JEE Main 2024 · 5 April · evening · Single correct · +4 / −1
Coagulation of egg, on heating is because of :
- (a) Denaturation of protein occurs
- (b) Biological property of protein remains unchanged
- (c) Breaking of the peptide linkage in the primary structure of protein occurs
- (d) The secondary structure of protein remains unchanged
Answer and solution
Answer (a) Denaturation of protein occurs
Solution
Chemistry ma’am · 3 steps
Heat breaks the weak bonds that hold the protein's shape, but the chain of amino acids stays intact.
- What heat does. Egg white is mostly globular protein, folded into a compact shape held by hydrogen bonds and other weak forces. On heating, these weak forces break and the chains unfold and tangle together into an insoluble mass.
- Name for it. Loss of the secondary and tertiary structure, with the protein losing its biological activity, is called denaturation. The covalent peptide bonds of the primary structure are not broken, so the amino acid sequence stays the same.
Level of structure Held by After heating Primary Covalent peptide bonds Unchanged Secondary (α-helix, β-sheet) Hydrogen bonds Destroyed Tertiary (overall folding) Hydrogen bonds, disulphide links, other weak forces Destroyed Biological activity Depends on the 3D shape Lost - So. Egg coagulates on heating because its protein is denatured, which is option (a).
The idea to keep. Denaturation unfolds a protein, wiping out its secondary and tertiary structure and its activity. The primary structure, the peptide-bonded sequence, survives.
Answer from the NTA final answer key. Solution by PrepWiser.