1. Plants Unit Activity 5.3: Explaining How Plants Grow: Biosynthesis
Carbon: Transformations in Matter and Energy
Environmental Literacy Project Michigan State University
Plants Unit Activity 5.3: Explaining How Plants Grow: Biosynthesis
Image Credit: Craig Douglas, Michigan State University

2. Plants Unit Map You are here (down the triangle) Application
Lesson 2: Foundations: Zooming into Organisms
Lessons 4 & 5: Explaining How Plants Make Food, Move, Function, and Grow
Lesson 3: Investigating Plants
Lesson 1: Pretest and Expressing Ideas
Lesson 1: Pretest and Initial Ideas
Lesson 6: Explaining Other Examples of Plant Growth and Functioning
Observations
Patterns
Models
Data from mass of plants growing from seed.
Data from plants in the light and dark with BTB.
Plants gain mass (more).
Soil loses mass (less).
Plants take in CO2 in the light.
Plants release CO2 in the dark.
Photosynthesis
Biosynthesis
Cellular Respiration
Pre Lesson: Investigation Set-Up
(up the triangle)
Inquiry
Evidence-Based Arguments
Model
(down the triangle)
Application
Observe
Coach
Use the instructional model to show students where they are in the course of the unit.
Show slide 2 of the 5.3 Explaining How Plants Grow: Biosynthesis PPT.
Pre Lesson
Pretest
Establish the Problem
Found-ational
Knowl-edge and Practice
Predict & Express Ideas
Fade
Post test
Maintain
Next Unit

3. Revisit your arguments
Think about what you know now that you didn’t know before. What have you learned?
Remind students of their unanswered questions.
Using slide 3 of the PPT have students revisit their arguments and unanswered questions from the Plant Investigation by looking at 5.2 Evidence-Based Arguments Tool for Mass Changes.
Remind students that after explaining cellular respiration and photosynthesis in Activities 4.2 and 4.4 there were still unanswered questions about how plants grow.
In today’s lesson, students will use what they learned in Activities 5.3 (and 5.4) to explain how plants get glucose to their cells and how plants use glucose for growth.

4. How do plants use food and minerals as materials for growth?
Image Credit: Craig Douglas, Michigan State University
Have students review the process of biosynthesis.
Use slides 4-5 of the 5.5 Explaining How Plants Grow: Biosynthesis PPT to guide students through a review of biosynthesis.
Ask students for their ideas about what they remember from the previous activity.

5. Biosynthesis Materials for growth: Biosynthesis Food To Cells
Energy: Cellular respiration
Image Credit: Craig Douglas, Michigan State University
Have students review the process of biosynthesis.
Use slides 4-5 of the 5.5 Explaining How Plants Grow: Biosynthesis PPT to guide students through a review of biosynthesis.
Ask students for their ideas about what they remember from the previous activity.

6. Constructing Explanations
Consider the following as you construct your explanation:
Evidence from the investigation
What you learned from the molecular modeling or tracing activity
Three Questions Handout
Have students complete their Explanations Process Tool for Biosynthesis.
Show slide 6 of the PPT. Give each student one copy of 5.5 Explanations Tool for Potato Biosynthesis.
Tell students that in this part of the investigation, they will combine everything they learned about how plants use food to grow into an explanation.
Remind them to consider both their evidence from the investigation as well as what they learned in the molecular modeling (or tracing) activity to construct their explanations.
Give students about 10 minutes to complete the Explanations process tool.

7. Comparing Ideas with a Partner
Compare your explanations for each of the Three Questions.
How are they alike?
How are they different?
Check your explanation with the middle- and right-hand columns of the Three Questions handout.
Consider making revisions to your explanation based on your conversation with your partner.
Have students share explanations with each other.
Show slide 7 of the PPT. Divide students into pairs and have them compare explanations for the Three Questions and the final explanation on the process tool.
Have students use the Three Questions 11 x 17 Poster (or Handout) as a reference. Have students check their explanations with the middle and right-hand columns of the poster or handout to make sure they are following the “rules.”

8. The Matter Movement Question
water
minerals
Glucose
Image Credit: Craig Douglas, Michigan State University
Have students think about how biosynthesis answers the Matter Movement question.
Use slides 8-9 in the PPT to have the students discuss what is happening to matter during biosynthesis and to have them check their answers to the Matter Movement Question on their 5.5 Explanations Tool for Potato Biosynthesis.
Show students slide 8-9 to have them think about where atoms are moving from and moving to during biosynthesis.
Display slides to have students compare their answers to the Matter Movement Question with the answers on the slide. Students only need to have arrows showing the movement of molecules into and out of the cell. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
Which atoms and molecules move so that plants can grow through biosynthesis?

9. How do glucose water, and minerals move for a plant stem cell to grow?
The Matter Movement Question
water
minerals
glucose
Image Credit: Craig Douglas, Michigan State University
Have students think about how biosynthesis answers the Matter Movement question.
Use slides 8-9 in the PPT to have the students discuss what is happening to matter during biosynthesis and to have them check their answers to the Matter Movement Question on their 5.5 Explanations Tool for Potato Biosynthesis.
Show students slide 8-9 to have them think about where atoms are moving from and moving to during biosynthesis.
Display slides to have students compare their answers to the Matter Movement Question with the answers on the slide. Students only need to have arrows showing the movement of molecules into and out of the cell. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
How do glucose water, and minerals move for a plant stem cell to grow?

10. Matter Movement Do you have:
an arrow showing small organic molecules or monomers (amino acids, sugars, and fatty acids) going into the potato cell?
Small Organic Molecules or Monomers
Image Credit: Craig Douglas, Michigan State University
Display slides to have students compare their answers to the Matter Movement Question with the answers on the slide. Students only need to have arrows showing the movement of molecules into and out of the cell. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.

11. Matter Movement Do you have:
an arrow showing soil minerals going into the potato cell?
Soil Minerals
Small Organic Molecules or Monomers
Image Credit: Craig Douglas, Michigan State University
Display slides to have students compare their answers to the Matter Movement Question with the answers on the slide. Students only need to have arrows showing the movement of molecules into and out of the cell. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.

12. Matter Movement Do you have:
large organic molecules (or polymers) staying in the potato cell?
Soil Minerals
Small Organic Molecules or Monomers
Image Credit: Craig Douglas, Michigan State University
Display slides to have students compare their answers to the Matter Movement Question with the answers on the slide. Students only need to have arrows showing the movement of molecules into and out of the cell. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
Large organic molecules or polymers

13. The Matter Change Question
What happens to small organic molecules during biosynthesis?
Chemical change
Image Credit: Craig Douglas, Michigan State University
Have students think about how biosynthesis answers the Matter Change Question.
Show slide 13 to begin discussing the Matter Change Question.
Display slides to have students compare their answers to the Matter Change Question on the 5.5 Explanations Tool for Potato Biosynthesis with the answers on the slide. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
Refer to the Digestion and Biosynthesis 11 x 17 Posters in your classroom to help students visualize the biosynthesis of monomers to polymers.
Note: If you taught only 5.3, you can use the posters to help students visualize the process, but do not need to focus on the names of the small organic molecules.
Small organic molecules (monomers)
go into cells, but don’t come out. What happens inside the cells?

14. Matter Change
Name the chemical change that potato cells use to build large organic molecules: Biosynthesis
Display slides to have students compare their answers to the Matter Change Question on the 5.5 Explanations Tool for Potato Biosynthesis with the answers on the slide. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
Refer to the Digestion and Biosynthesis 11 x 17 Posters in your classroom to help students visualize the biosynthesis of monomers to polymers.
Note: If you taught only 5.3, you can use the posters to help students visualize the process, but do not need to focus on the names of the small organic molecules.

15. Matter Change
What molecules are carbon atoms in after the chemical change? Large organic molecules (or carbohydrates, Fats/Lipids, and Proteins) What other molecules are produced? Water
What molecules are carbon atoms in before the chemical change? Small organic molecules (or monomers such as amino acids, sugars, and fatty acids) What other molecules are needed? None
Chemical Change
Display slides to have students compare their answers to the Matter Change Question on the 5.5 Explanations Tool for Potato Biosynthesis with the answers on the slide. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
Refer to the Digestion and Biosynthesis 11 x 17 Posters in your classroom to help students visualize the biosynthesis of monomers to polymers.
Note: If you taught only 5.3, you can use the posters to help students visualize the process, but do not need to focus on the names of the small organic molecules.

16. Energy Change
What forms of energy go into this chemical change? Chemical Energy
What forms of energy come out of this chemical change? Chemical Energy
Energy Transformation
Discuss how biosynthesis helps answer the Energy Change questions.
Display slide 16 to have students compare their answers to the Energy Change Question on the 5.5 Explanations Tool for Potato Biosynthesis with the answers on the slide. Have students use a different colored writing utensil to make any needed changes to their answers. Allow students to ask questions if they do not understand why their ideas are incorrect.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.

17. Telling the Whole Story
Question: How does a cell in the root of a potato use food to grow and divide?
Does your story include these parts? (Check the back of the Three Questions Handout.)
Matter movement: Small organic molecules (monomers, such as amino acids, sugars, fatty acids, and glycerol) and minerals from the soil enter the potato cell.
Matter change: The small organic molecules (monomers) and soil minerals are combined together to make large organic molecules (polymers), such as carbohydrates, fays/lipids, and proteins. Water is produced during this process.
Energy change: The chemical energy stored in the C-C and C-H bonds in the small organic molecules (monomers) stays in these bonds when they are combined into large organic molecules (polymers). The polymers still have chemical energy in C-C and C-H bonds after biosynthesis.
Matter movement: The cell grows bigger and may eventually divide as more large organic molecules (polymers) are made.
(Optional) Have students critique example explanations
Display Slide 17 of the PPT. Have students look at two handouts: (a) the Three Questions Handout, and (b) the Plants Example Explanations Handout.
Ask students to evaluate the two example explanations of biosynthesis on the Plants Example Explanations Handout: Which explanation is better? Why?
Have students use the Three Questions Explanation Checklist on the back of the Three Questions Handout to justify their critiques of the explanations.
Have students critique and improve their full explanations.
Display slide 17 of the PPT for the full explanation. Have students use the Three Questions Explanation Checklist on the back of the Three Questions Handout to check that their story includes each of the parts (matter movement, matter change, energy change, and matter movement) and answers the prompt in a cohesive way.
If students don’t have all four parts in their explanation, instruct them to add to their explanation using a different colored writing utensil.
If students have model explanations to share, display student work and discuss. If students have common areas of weakness in their explanations, ask for a volunteer to share, display student work, and discuss ways of strengthening the response.
Have students read about biosynthesis and complete part of the graphic organizer.
Pass out 5.3 How do Plants Use Food to Grow? Reading. The reading provides a summary explanation of photosynthesis and additional information about other metabolic pathways. Students can complete the reading individually or in pairs.
After reading, students can complete the biosynthesis section of the Matter and Energy in Plants Graphic Organizer.
(Optional) Have students complete the Big Idea Probe: Houseplant for a Busy Family for the second time.
If you decided to use the Big Idea Probe: Houseplant for a Busy Family, have students complete it and share their ideas for a second time. See Assessing the Big Idea Probe: Houseplant for a Busy Family for suggestions about how to use the Big Idea Probe.