Topic Four (1.4): Enzymes

 Introduction

The fourth topic focuses on enzymes and how they work as catalysts.

The action of enzymes is essential to many processes in all living organisms. You must be able to explain that enzymes have a specific shape that is complimentary to their substrate (the chemical they are breaking down) and that the substrate binds to the enzyme to form an enzyme-substrate complex. This is why each different process has its own enzyme.

You must also be able to explain how changes in concentration, pH and temperature affect enzyme activity and be prepared to apply these concepts to new situations in exam questions. It’s very common to have to explain the effects of both high and low temperature on enzyme action: make sure you discuss reduced collisions at low temperatures and denaturing at high temperatures.

The following key areas are covered in this topic:

  • Enzymes – What They Are and How They Work
  • Factors That Affect Enzyme Action
  • Denaturation

Topic Three is broken down into the following study sessions:

Session One (1.4.1): Enzymes

Session Two (1.4.2): Factors that Affect Enzyme Action

Session Three (1.4.3): Denaturation