The Digestive System
Students will plan & conduct an experiment to illustrate the necessity of mechanical digestion for efficient chemical digestion and analyze the activity of digestive enzymes within different organs of the digestive tract, connecting enzyme function to environmental factors such as pH, temperature, concentration, etc.
Overview
Students begin by observing bananas and crackers and building a model of the digestive system. In a macromolecule lab, they use Biuret, Benedict's, Sudan III, and Lugol's iodine solutions to identify macromolecules in simulated stomach content. Students then design a procedure using amylase, lipase, and protease to break down those macromolecules and confirm the results with the same tests, observing over about a week. They also plan an experiment showing that mechanical digestion supports chemical digestion. Students write a formal lab report, alter conditions such as pH and temperature, and present results as a poster, slide show, or video. Engagement is 1 period, exploration 1 period plus 15 minutes daily for a week, explanation 2-3 days, elaboration 1 day plus a week, evaluation 2-3 periods.
Lesson Objectives
- Plan & conduct an experiment to illustrate the necessity of mechanical digestion for efficient chemical digestion and analyze the activity of digestive enzymes within different organs of the digestive tract, connecting enzyme function to environmental factors such as pH, temperature, concentration, etc.
Standards
NGSS · 3
- HS-PS1-5Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs.
- HS-LS1-1Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions.
- HS-LS1-2Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
CCSS Math · 4
- HSS-ID.C.9Distinguish between correlation and causation.
- HSS-MD.B.7Analyze decisions and strategies using probability concepts.
- HSN-Q.A.1Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.
- HSN-Q.A.3Choose a level of accuracy appropriate to limitations on measurement when reporting quantities.
CCSS ELA · 1
- SL.11-12.1.aCome to discussions prepared, having read and researched material under study; explicitly draw on that preparation by referring to evidence from texts and other research on the topic or issue to stimulate a thoughtful, well-reasoned exchange of ideas.