Q4 / 200 · MHT CET - Medical 2026 (23 April Shift 2) · Biology
An enzyme catalyzes a reaction at a high rate at $37^\circ$C but becomes inactive at $60^\circ$C. This is because
- Correct answerAThe enzyme is denatured at high temperature.
- BThe enzyme is activated only at low temperature
- CThe substrate becomes inactive at high temperature.
- DThe enzyme-substrate complex becomes more stable
Solution
Enzymes are generally proteinaceous in nature and have a specific three-dimensional structure that forms their active site. They work optimally at a specific temperature, which is around $37^{\circ}$C for most human enzymes.
At high temperatures such as $60^{\circ}$C, the thermal energy disrupts the weak interactions (like hydrogen bonds and hydrophobic interactions) that maintain the enzyme's tertiary structure. This causes the enzyme to unfold and lose its specific shape, a process known as denaturation.
Once denatured, the active site is destroyed, and the enzyme can no longer bind to its substrate, rendering it inactive.
Answer: The enzyme is denatured at high temperature.
At high temperatures such as $60^{\circ}$C, the thermal energy disrupts the weak interactions (like hydrogen bonds and hydrophobic interactions) that maintain the enzyme's tertiary structure. This causes the enzyme to unfold and lose its specific shape, a process known as denaturation.
Once denatured, the active site is destroyed, and the enzyme can no longer bind to its substrate, rendering it inactive.
Answer: The enzyme is denatured at high temperature.
Hence, the correct answer is option: 'A'.