Final answer:
The rate of an enzyme-controlled reaction would increase if the temperature was raised from 20°C to 30°C.
Step-by-step explanation:
The rate of an enzyme-controlled reaction would increase if the temperature was raised from 20°C to 30°C. This is because an increase in temperature generally increases the rate of chemical reactions, including enzyme-catalyzed reactions. When the temperature rises, more molecules have enough energy to overcome the activation energy barrier, which leads to an increase in reaction rate.