How do enzymes react under different temperatures?

A graph would be drawn to show a steady incline to an optimum temperature and then a sharp decrease after the peak.

As the temperature increases the enzyme and sustrate will have more kinetic energy and so enzyme-substrate collsions are more likely occur until the optimum temperature. (Note that this is usually around 37 degrees but can vary depending on the enzyme).Here is the highest rate of reaction. Past this point the enzymes will begin to denature. This is where the active site changed shape and so the substrate cannot fit into the active site and so the rate will decrease rapidly.