Three-dimensional Learning Progression The three activities in this lesson complete the Explanations Phase of the Animals unit. This involves modeling and coaching with the goal of helping students develop atomic-molecular scale accounts of the digestion, and biosynthesis that were drivers of the macroscopic changes they observed in their Mealworms Eating investigation in Lesson 3. Key Ideas and Practices for Each Activity Activity 5.1 is the first part of the Explanations Phase of the instructional model (going down the triangle) for digestion and biosynthesis. Students trace the chemical changes of digestion and biosynthesis in the body of a cow using a poster of a cow. Activity 5.2 is a 2-turtle activity appropriate for advanced middle school or high school students and classes. If you decide not to teach 5.2, you can move directly from 5.1 to 5.3. In 5.2, students model the chemical changes of digestion and biosynthesis using paper molecules. This activity introduces and uses the vocabulary of polymer and monomer, as well as the names of specific monomers. Activity 5.3 is the second part of the Explanations Phase of the instructional model (going down the triangle) for digestion. Students use the Explanations Tool to construct final explanations of what happens when animals break large organic molecules from their food into small organic molecules. This activity is appropriate for students who did only 5.1 and students who did both 5.1 and 5.2, but the vocabulary used to describe the molecules will be different depending on what activities were taught. Ideally, at this phase their explanations will combine evidence from macroscopic-scale observations during the investigation with their new knowledge of chemical change at the atomic-molecular scale. Activity 5.4 continues the second part of the Explanations Phase of the instructional model (going down the triangle) for biosynthesis. Students use the Explanations Tool to construct final explanations of what happens when animals use small organic molecules to gain mass. This activity is appropriate for students who did only 5.1 and students who did both 5.1 and 5.2, but the vocabulary used to describe the molecules will be different depending on what activities were taught. Ideally, at this phase their explanations will combine evidence from macroscopic-scale observations during the investigation with their new knowledge of chemical change at the atomic-molecular scale. Key Carbon-Transforming Processes: Digestion and Biosynthesis Content Boundaries and Extensions
