Factors affecting Enzymes
Temperature
- Temperature
affects the action of enzymes, as higher temperatures increase the rate of reactions as the enzyme and substrate gain kinetic energy, meaning they collide
more frequently and successfully.
- But
once the enzyme has passed its optimum
temperature, it becomes denatured,
as the proteins of the enzyme are broken down by heat, and the active site changes shape and no longer
is complementary to the substrate.
pH
- Most
enzymes have evolved to have an optimum
pH of 7, or neutral. Some enzymes do however have different optimums,
depending on the conditions in which they function, e.g. pepsin in the stomach has a pH of about 2.
- The
closer the pH is to the optimum, the better it will work. But if it is too far
either side of the optimum pH, the enzyme can become denatured and the active site could change shape and no longer
function
Concentration of enzyme and substrate concentration
- Greater concentration causes an increase in the rate of reactions, as
there is a greater likelihood of collisions
between the enzyme and substrate.
- However, the concentration of the other concentration (the one we are keeping constant) starts to become the limiting factor
- i.e. when increasing enzyme concentration, the substrate becomes the limiting factor and vice versa
