What is the temperature optimum for a human enzyme?

• A. It is greater than 37°C because it may be adapted to function efficiently at body temperature.
• B. It is exactly 37°C.
• C. It is 25°C.
• D. It is below 0°C.

Answer: (A)

Enzyme activity depends on temperature, with a peak at the temperature where the enzyme is most stable and active. In humans, enzymes are tuned to the body’s stable internal temperature, around 37°C. The idea behind the correct choice is that the optimum temperature reflects adaptation to functioning efficiently in that physiological environment—so the optimum is at or around body temperature, not at room temperature or below. The option stating the optimum is greater than 37°C conveys this adaptation to the human body's warm environment, which best aligns with how human enzymes have evolved to work most effectively. Enzymes don’t generally have their peak activity at room temperature (25°C) or freezing conditions, and while some may be near 37°C, the emphasis is on harmony with body temperature.