When you increase the temperature, the rate of enzyme activity typically increases up to a certain point, as higher temperatures provide more kinetic energy to the enzyme and substrate, leading to more frequent collisions and interactions. However, if the temperature rises beyond an optimal range, the enzyme can become denatured, losing its specific structure and function.
When you decrease the temperature, the activity of the enzyme generally decreases, as lower temperatures result in reduced kinetic energy, leading to fewer collisions between the enzyme and substrate and, therefore, slower reaction rates.
Most enzymes become denatured at temperatures above their optimal range, which usually falls between 37°C to 50°C, depending on the specific enzyme. For many human enzymes, denaturation can occur around 50°C to 60°C, but some thermophilic enzymes may withstand much higher temperatures without denaturing.