These activities can be used in the teaching of the topic "Enzymes" at KS4. It is envisages that lessons would run in the following sequence: 1. What are enzymes and how do they work? Use one of the experiments from "Enzymes Experiments" plus text activity 1 from "Industrious Microbes". 2. What factors affect the rate of enzyme activity? Again, use one or more experiments from the first resource along with text activity 2 from "Industrious Microbes". 3. How are enzymes used in respiration? Use activities from "Staying Alive" to teach about the processes of aerobic and anaerobic respiration. 4. How are enzymes used in digestion? Two to three lessons could be spent using the activities in "Staying Alive" to teach about the process of digestion and the enzymes involved. 5. What other uses do enzymes have? One to two lessons could be used to work through the remaining activities on "Industrious Microbes", followed by "Enzymes outside the body" if appropriate. 6. Either as a lesson or for homework, students can work through the website "Enzyme Action" to summarise the topic or for revision.