1. Enzymes have an active site to which specific substrates bind.

2. Enzyme catalysis involves molecular motion and the collision of substrates with the active site.

3. Temperature, pH and substrate concentration affect the rate of activity of enzymes. [Students should be able to sketch graphs to show the expected effects of temperature, pH and substrate concentration on the activity of enzymes. They should be able to explain the patterns or trends apparent in these graphs.]

4. Enzymes can be denatured.

5. Immobilized enzymes are widely used in industry.

Methods of production of lactose-free milk and its advantages. [Lactase can be immobilized in alginate beads and experiments can then be carried out in which the lactose in milk is hydrolysed.]

1. Design of experiments to test the effect of temperature, pH and substrate concentration on the activity of enzymes.

2. Experimental investigation of a factor affecting enzyme activity. (Practical 3)