Transformations in Matter and Energy Carbon TIME is an NSF-funded partnership led by Michigan State University
Decomposers | Lesson 5 - Explaining How Decomposers Grow
Students use a scientific model to explain digestion and biosynthesis using the Three Questions.
How do decomposers use food to grow?
Activities in this Lesson
- Activity 5.1: Tracing the Processes of Decomposers Growing: Digestion and Biosynthesis (40 min)
- Activity 5.2: Molecular Models for Fungi Growing: Digestion and Biosynthesis (40 min)
- Activity 5.3: Explaining How Fungi Grow: Digestion (40 min)
- Activity 5.4: Explaining How Fungi Grow: Biosynthesis (40 min)
Note: The molecular modeling part of Activity 5.2 is exactly the same as the molecular modeling for biosynthesis in the Plants and Animals units. Additionally, it is a 2-turtle activity which means it involves a higher level of complexity. Consider skipping the activity if you have already taught it in another unit or if it is too advanced for your class.
Lesson 5 – Explaining How Decomposers Grow (students as explainers)
Activity 5.1: Tracing the Processes of Fungi Growing: Digestion and Biosynthesis
Students “zoom in” to the structure and function of a mushroom’s organ systems and cells, tracing atoms and energy.
(Optional) Activity 5.2: Molecular Models for Fungi Growing: Digestion and Biosynthesis
Students use molecular models to explain how polymers are broken into monomers during the process of digestion and monomers are linked into polymers during biosynthesis.
Activity 5.3: Explaining How Fungi Grow: Digestion
Students explain how matter moves and changes and how energy changes during digestion by a fungus.
Activity 5.4: Explaining How Fungi Grow: Biosynthesis
Students explain how matter moves and changes and how energy changes during biosynthesis in a mushroom’s cells.
NGSS Performance Expectations
- Chemical Reactions. HS-PS1-4. Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends on the changes in total bond energy.
- Chemical Reactions. HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
- From Molecules to Organisms: Structures and Processes. HS-LS1-2. Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
- Matter and Energy in Organisms and Ecosystems. HS-LS1-6. Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.
- Structure and Properties of Matter. MS-PS1-1. Develop models to describe the atomic composition of simple molecules and extended structures.
- Chemical Reactions. MS-PS1-5. Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
- From Molecules to Organisms: Structures and Processes. MS-LS1-3. Use argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells.
- Matter and Energy in Organisms and Ecosystems. MS-LS1-7. Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism.
Talk and Writing
This lesson of the unit represents the fading portion of the Explanations Phase. This means that students are expected to develop explanations for carbon-transforming processes they studied in this unit in new and novel contexts. The table below shows specific talk and writing goals for the Explanations phase of the unit.
Talk and Writing Goals for the Explanations Phase
Teacher Talk Strategies That Support This Goal
Curriculum Components That Support This Goal
Examine student ideas and correct them when there are problems. It’s ok to give the answers away during this phase! Help students practice using precise language to describe matter and energy.
Let’s think about what you just said: air molecules. What are air molecules?
Are you talking about matter or energy?
Remember: atoms can’t be created. So that matter must have come from somewhere. Where did it come from?
Let’s look at the molecule poster again… is carbon an atom or a molecule?
Three Questions Poster
Focus on making sure that explanations include multiple scales.
The investigation gave us evidence for what was happening to matter and energy at a macroscopic sale. But what is happening at an atomic-molecular scale?
What is happening to molecules and atoms?
How does energy interact with atoms and molecules during chemical change?
Why doesn’t the macroscopic investigation tell us the whole story?
Let’s revisit our scale poster… what is happening to matter at the molecular scale?
Molecular Modeling Worksheets
PPT Animation of chemical change
Powers of Ten Poster
Encourage students to recall the investigation.
When did this chemical change happen during our investigation?
How do we know that? What is our evidence?
What were the macroscopic indicators that this chemical change took place?
Evidence-Based Arguments Tool
Elicit a range of student explanations. Press for details. Encourage students to examine, compare, and contrast their explanations with others’.
Who can add to that explanation?
What do you mean by _____? Say more.
So, I think you said _____. Is that right?
Who has a different explanation?
How are those explanations similar/different?
Who can rephrase ________’s explanation?