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Integrating Lecture, Laboratory, and Literature using Case Studies . Ann T.S. Taylor Chemistry Department Wabash College Crawfordsville, IN 47933. What are your non-content course goals?. The Context: Che 361. Required course for Chemistry majors Most Chem minors also take the course
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Integrating Lecture, Laboratory, and Literature using Case Studies Ann T.S. Taylor Chemistry Department Wabash College Crawfordsville, IN 47933
The Context: Che 361 • Required course for Chemistry majors • Most Chem minors also take the course • Organic II prerequisite • Typical enrollment: 24-30 students, 8-12 per lab section • Three 50 minute class periods and one three hour lab per week
Che 361: Biochemistry non-content goals • Cooperative learning strategies • Transferrence and connections • Application, not only memorization • Cultivate intellectual curiosity • Requires critical thinking skills • Oral and written communication skills • Use bioinformatic and modeling tools
Common features my cases • A short real-life story • Reading review and primary literature articles • Short in-class small group activities which connect the case and lecture • Laboratory activities that directly relate to the case • Computational activity
The Case of the Tainted Tacos A Case Study on Genetically Modified Foods which integrates laboratory, lecture, and literature
Unit goals Students should be able to: • Explain transcription and translation • Design PCR probes for a sequence of interest • Understand how transgenic organisms are made • Reinforce principles of enzymology, protein structure, and membrane transport • Resolve conflicting data sets • Understand the broader ethical implications of using GM foods
The Case of the Tainted Tacos The Setup Story
Questions generated by story • How are GM foods made? • How do GM foods “work”? • Are GM foods safe for the environment? • Could weeds become resistant to herbicides? • Are GM foods safe for humans? • Do farmers really benefit from using GM products? • Should I eat GM foods? Do I already eat GM foods?
Case teaching strategies • Common study areas • Specialization • Jigsawing
Questions all groups study • What are the most common genetic modifications of foods • How genetic modifications are made • How genetic modifications can be detected, and how these methods work • Design the primers that are used in the lab
Specialist groups Farmers • Study the economic impact of GM foods and how RoundUp Ready products work Entomologists • Study the mechanism of Bt products and their impact upon other insects Immunologists • Look at methods to predict allergenicity
Linking Literature • Guided reading questions • Small group problems • Literature searches
Example: Farmers Read three papers, then answer questions such as: • Why do farmers use genetically modified plants? • When do farmers benefit economically from using GM crops? • Why does RoundUp (glyphosate) affect plants but not animals? • How does glyphosate affect EPSPS, both structurally and kinetically? • Describe in detail how weeds that are resistant to RoundUp differ from wildtype (normal) plants.
Goals: Better pest management Increase yield Reduce pesticide use More flexibility Disadvantages: Only profitable when infestation cost is greater than tech cost Unknown effect on soil ecology Development of “superweeds” Economic impact of GM crops
Integrating technology • Presentations • Research techniques with guided directions • Tools and tutorials from the internet
Computational analysis of Cry9 for allergenicity • Does it have homology to known allergens? • BLAST search of allergen database • STGSST (422-428) is identical to a sequence in aAspergillus fumigatus allergen • Is the homology in a hydrophilic region? • No—from a computational tool discussed in one of the papers
Linking lab Do an experiment related to the issue! • Sources: • Adapt an existing lab • Adapt a “real world” technique • Adapt an experiment from one of the papers • Adapt a published teaching lab (Biochemistry and Molecular Biology Education, Journal of College Science Teaching, Journal of Chemical Education) • Work on the case during lecture and lab
Typical lab results 1 2 3 4 5 6 7 8 9 10 2000 1000 500 300 200 • Lane 1, Arrowhead Mills corn meal; lane 2, Kroger corn meal; lane 3, Quaker white corn meal; lane 4, Cotton Pickin’ corn muffin mix; lane 5, Jiffy corn muffin mix; lane 6,Gold Medal corn muffin mix; lane 7, Aunt Jemima corn bread mix; lane 8, Martha White corn muffin mix; lane 9, non-transgenic corn seed; lane 10, Pioneer YieldGard corn seed.
Other examples • Olestra case • http://www.providence.edu/chm/kcornely/Casebook.htm • extract & digest lipids from potato chips • Drug discovery • HIV protease kinetic analysis • structure exploration • Drug discovery lab (BAMBED(2005) 33: 16 – 21)
References • Case study: • Advanced version: http://www.sciencecases.org/gmo/gmo_adv.asp • GOB version: http://www.sciencecases.org/gmo/gmo_gen.asp • Also published in JCST (2005) 34(2): • Lab experiments: • Taylor, J Chem Ed (2005) 82 (4): 597-598. • Brinegar & Levee BAMBED (2004) 32: 35-38. • http://www.greenomes.org/
Case study collections • https://chico.nss.udel.edu/Pbl/ (requires password) • http://www.fhs.mcmaster.ca/pbls/writing/ • http://ublib.buffalo.edu/libraries/projects/cases/ubcase.htm • K. Cornely, Cases in Biochemistry, John Wiley & Sons, 1999; also at http://www.providence.edu/chm/kcornely/Casebook.htm