AQA A level Biology Specificaton Unit 1 Biological Molecules Topic: 1.4.2 Many proteins are enzymes NOT THE REQUIRED PRACTICAL This lesson covers: 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 enzymecontrolled reactions – enzyme concentration, substrate concentration, concentration of competitive and of noncompetitive 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. To complete the lesson provide students with related past exam questions