Quantitating Enzyme Activity Using Starch-Agar Gels.

The objectives of this week-long lab were to introduce plant science into the biology classroom, use hands-on experiments to illustrate enzyme activity in plants (starch synthesis and digestion) and mammals (starch digestion), and to integrate math and language learning objectives into the science curriculum.  Algebra, geometry and graphing have been incorporated into this lab where students measure enzyme activity as starch is broken down during seed germination.  Hands-on experiments use seeds from grains and legumes, saliva, starch-agar gels, and the starch indicator, iodine, to illustrate digestion and quantitate enzyme activity.  Students learn what an enzyme is and how it works as they create ‘Smiling Faces’ with saliva and corn.  We discuss the role enzymes play in seed germination and food digestion.  Students ‘see’ the varying amounts of enzyme present in germinating field, sweet, pop, and Indian corn seeds, other grains, as well as in many legumes when they stain starch-agar gels with iodine and discover clear regions on the gels denoting specific areas of starch digestion.  High school students use the starch-agar gels containing seeds from grains and legumes germinated at different dates to visualize starch utilization and quantitate changes in amylase activity over time.  Glucose test strips are incorporated into this lab to show the students that the product of starch digestion is the sugar, glucose.  Germinating seeds are weighed throughout the experiment and students create growth curves.  Students then correlate enzyme activity/starch digestion with plant growth.  Jigsaw puzzles and Lego^TM blocks are utilized to enable students to better understand concepts of biosynthesis, enzyme specificity and an enzyme's role in polymerization.  Throughout this week-long lab students are introduced to plant science, learn about enzyme function in plants and animals, incorporate math into their lab analysis, and apply language skills as they summarize their findings in a report.  Throughout this week-long lab teachers engage students in many science activities covering multiple curriculum topics and are able to evaluate students’ understanding of the concepts covered.