Question

students compare enzyme activity at 10°c, 25°c, and 40°c. the fastest reaction occurs at 25°c. what is the best explanation?
substrate concentration was highest at 25°c
25°c is the enzymes optimal temperature
enzymes are inactive at low temperatures
40°c is too cold for enzymes

Explanation:

Enzymes have an optimal temperature at which their activity is highest. When the temperature is lower (like \(10^{\circ}C\)), the enzyme activity is reduced (but not completely inactive as enzymes are proteins and at low temperatures their kinetic energy is just low, not zero). When the temperature is too high (like \(40^{\circ}C\) might be for some enzymes, depending on the enzyme type, but in this case since \(25^{\circ}C\) is the best), it can start to denature the enzyme (change its shape). The substrate concentration is not indicated to vary with temperature in the problem statement.

Answer:

\(25^{\circ}C\) is the enzyme’s optimal temperature.