We opened class with a brainstorming session about what would happen if a person placed a Saltine cracker in their mouth and left it there. Students in each class came up with two or three hypothesis statements, after which, they conducted the experiment. Students were offered regular or whole wheat crackers. We recorded observations, determined whether the observations supported or disproved the hypothesis statements, and then launched into a discussion of enzymes. Students recorded the definitions of reactants, products, and enzymes taken from today’s Chemistry class Lesson 35 PowerPoint slide deck (on slide 11, the word “catalyst” was replaced with “enzyme” and “substance” was replaced with “protein”). We reviewed the way that animals and plants created polymers of glucose to create glycogen (energy stored in animals), starch (energy stored in the plant organelle called the amyloplast), and cellulose (structural molecule in plants). We then applied that learning to the discussion of how the salivary amylase enzyme digests the starch in the Saltine crackers, releasing glucose molecules. A few students in each class who let the crackers sit in their mouths for a long time even reported the crackers tasted slightly sweet. The discussion of enzymes set the stage for tomorrow’s potato catalase lab.
Pictures from the white boards for today’s classes: