Jessie was teaching her students about properties of enzymes and enzyme activities. She started off by conducting - and demonstrating to students - an experiment involving yeast & hydrogen peroxide.

Students were not told what the contents were. In the experiment, the enzyme catalase in yeast cells catalysed the breakdown of hydrogen peroxide into water and oxygen gas (which was given off as effervescence bubbles). 

Students were asked to provide a hypothesis of what they thought the contents were. They were allowed to hold the test-tube and smell the mixture inside, and were encouraged to ask questions about the experiment. Their ideas and questions were posted on KF (Fig. 1).

Fig. 1. KF view for the topic on Enzymes.

Fig. 1. KF view for the topic on Enzymes.

In following lessons, students were instructed to comment and build on each other's responses. Some students googled for information on yeast and enzymes as well. This sequence of lessons led students to think about where enzymes are found, e.g., human body, which eventually led on to next chapter of Nutrition in Man.