The Challenge to Deliver Insulin
curriculum unit is intended primarily for the high school biology and chemistry classroom. This unit includes background on chemistry and cellular functioning as it relates to diabetes. Main instructional topics include protein chemistry, transcription, translation, and insulin evolution. Classroom activities that investigate these fundamental chemical and cellular processes are included to bring the unit directly to the students' lab bench.
Protein synthesis is a complicated, abstract concept for students to master, and the model of a familiar disease should make the topic more relevant and engaging.
Genetic engineering and microbiology is a topic that is frequently misunderstood by students. In the case of insulin, inserting the human genetic code for insulin into
bacteria allows pharmaceutical companies to manufacture insulin that is safe to use in people, as it is identical to the insulin that is found in their own bodies. Insulin production is an illustration of how modern medicine is a combination of scientific knowledge, careful experimentation, successful application, and practice that saves human lives.
Students do not readily accept that bacteria exist everywhere. There are more bacteria in the average human intestinal tract than there are humans on earth! While some bacteria are pathogenic, most are not. Bacteria play extremely important roles in modern medicine - both as a source for biomolecules such as insulin and as a nettlesome invader in tissue engineering and when introducing new devices to the human body.
Bacteria and other cell types have had their genomes successfully altered in the name of modern medicine in many other situations. For example, erythropoietin has been cloned to treat anemia, granulocyte-colony stimulating factor has been cloned to treat blood disorders, interferons have been cloned to act as anti-viral and anti-tumor agents, and nerve growth factor (NGF) has been cloned to promote nerve damage repair. (1)
Insulin is also an interesting molecule to consider with respect to the evolution of myriad different organisms. Sugars are a very convenient food source for most organisms, and the molecular relationship among different species' insulins is interesting to examine.