Each enzyme lowers the activation energy of the reaction it catalyses.

The induced-fit model of enzyme action.

The properties of an enzyme relate to the tertiary structure of its active site and its ability to combine with complementary substrate(s) to form an enzyme-substrate complex.

- The specificity of enzymes
- The effects of the following factors on the rate of enzyme-controlled reactions – enzyme concentration, substrate concentration, concentration of competitive and of non-competitive inhibitors, pH and temperature.

Students should be able to:

- appreciate how models of enzyme action have changed over time
- appreciate that enzymes catalyse a wide range of intracellular and extracellular reactions that determine structures and functions from cellular to whole-organism level.

Required practical 1

Investigation into the effect of a named variable on the rate of an enzyme-controlled reaction.