JEE Main levelSingle correct optionDifficulty 2 of 3bm093
Which statement correctly describes the denaturation of a protein by heat?
AOnly the primary structure is destroyed.
BThe protein always regains its native form on cooling.
CThe amino acid sequence is unchanged but the native three-dimensional shape and biological activity are lost.
DPeptide bonds are hydrolysed to free amino acids.
Answer: C
Heating disrupts hydrogen bonds and other weak interactions, so secondary and tertiary structures unfold and activity is lost. Peptide bonds survive, and changes such as the coagulation of egg white are irreversible.