Substrate & enzyme concentration & enzyme activity (Edexcel A-level Biology B)

This fully-resourced lesson describes how enzyme and substrate concentration affect the rate of enzyme activity. The PowerPoint and accompanying resources are the last in a series of 3 lessons which cover the detail of point 1.5 (iv) of the Edexcel A-level Biology B specification.

The first part of the lesson describes how an increase in substrate concentration will affect the rate of reaction when a fixed concentration of enzyme is used. Time is taken to introduce limiting factors and students will be challenged to identify substrate concentration as the limiting factor before the maximum rate is achieved and then they are given discussion time to identify the possible factors after this point. A series of exam-style questions are used throughout the lesson and the mark schemes are displayed to allow the students to assess their understanding and for any misconceptions to be immediately addressed. Moving forwards, the students have to use their knowledge of substrate concentration to construct a graph to represent the relationship between enzyme concentration and rate of reaction and they have to explain the different sections of the graph and identify the limiting factors.
The final section of the lesson describes how the availability of enzymes is controlled in living organisms. Students will come to recognise that this availability is the result of enzyme synthesis and enzyme degradation and their recall of transcription and translation is tested through a SPOT the ERRORs task.

Please note that this lesson explains the Biology behind the effect of concentration on enzyme-controlled reactions and not the methodology involved in carrying out such an investigation as this is covered in a core practical lesson.