What happens to the enzyme at around 40°C in a reaction?

• A. The enzyme becomes more active at this temperature.
• B. The enzyme may start to denature and lose its functionality.
• C. The enzyme changes its primary sequence.
• D. The enzyme becomes permanently active.

Answer: (C)

Temperature shapes enzyme activity by affecting both reaction rates and the protein’s stability. As temperature rises, molecules move faster, so reactions can speed up up to the enzyme’s optimum. Beyond that point, heat disrupts the weak bonds that hold the enzyme’s folded shape together, causing denaturation. Around 40°C, many enzymes begin to unfold, altering or destroying the active site and making the enzyme lose its function. The primary amino acid sequence is set by the genetic code and isn’t changed by normal temperature changes. Heat doesn’t typically make enzymes permanently active; it more often inactivates them by denaturing their structure. So the most accurate outcome is that the enzyme may denature and lose functionality.