Whenever possible, I try to make course content meaningful and relevant to my students' lives. When studying the digestive system, for instance, I placed an emphasis on nutrition and thinking about our own food intake. Students kept food diaries and used a meal from their own diet to exemplify the digestive process in a final creative writing assessment.
To study what nutrients are present in common foods, we conducted a lab investigation testing various foods for the presence of sugars, starches, protein, and fat. To draw out students' prior knowledge and potential misconceptions, I first had students categorize the given foods under the various categories of biomolecules. Then they worked in groups to carry out the investigation, and re-categorized each food according to their findings. Many of them were surprised to discover that milk contained sugar and that strawberries contained protein. These findings opened the door to explanations of what sugar and protein really were.
Download the lab handout: macromolecule lab.doc
Another interesting occurrence was that many students "found" that the soda sample contained sugar, even though I had secretly given them diet soda to test. Some students admitted that the visual results were not convincing when they tested the soda for sugar, but that they recorded a positive result anyway because they "knew" that it "must" contain sugar. Other students were more cautious and asked me if I had given them diet soda. This opened up a discussion about the role of bias and the influence of preconceptions in scientific investigations. The students were reminded of the importance of "trusting the data" as a tenet of scientific empiricism.
Below is an example of a student's lab handout from the food lab.