As with many chemical reactions, the rate of an enzyme-catalysed reaction increases as the temperature increases.This is because the molecules have more kinetic energy and move faster so there are more frequent and more successful collisions and more E-S complexes are formed per unit time.However, at high temperatures the rate decreases again because the enzyme becomes denatured and can no longer function.Different organisms live in a wide variety of habitats under a wide variety of conditions, therefore different enzymes have different optimum temperatures and different pH values at which they work best.Thermus aquaticus are thermophilic bacteria that live in hot springs. Their enzymes work best at high temperatures.The optimum temperature for their enzymes is 95°C and the enzymes continue to be effective at over 100°C.Shrimps that live in Arctic water have enzymes that work best about 4°C and denature at about 15°C.
Thermus aquaticus