1. What Do Soil, Air, and Water Give to Plants
What Do Soil, Air, and Water Give to Plants? Purpose: Create a skit/drama performance to illustrate matter going into the plants and where it comes from. Scene 1: Photosynthesis What molecules move into and out of plant for photosynthesis? Where does this happen? When does this happen? Scene 2: Cellular Respiration What molecules move into and out of plant for cellular respiration? Where does this happen? When does this happen?   Scene 3: Biosynthesis What molecules move through the plant system for biosynthesis? Where does this happen? Why does this happen?   Scene 4: Soil Minerals What atoms and molecules are dissolved in the water it takes in from the soil? In particular, how is nitrogen used by the plant?   Scene 5: Dry Mass of Plants What molecules make up the dry mass of plants? What atoms make up the dry mass of plants? Does the following contribute to the plants dry mass: Water, Soil Minerals, Air
Image Credit: Craig Douglas, Michigan State University

2. What atoms make up the dry mass of plants?
STARCH
FATS
GLUCOSE (SUGAR)
Image Credit: Craig Douglas, Michigan State University
Tell students that since “atoms last forever” these atoms must have come from somewhere. Ask: Where did they come from?
Tell students that first we need to identify which atoms make up a plant’s dry mass, and use Slide 2 to have student guess which atoms are the most important.
CELLULOSE (FIBER)
PROTEIN
You might be able to guess by thinking about the molecules in plants

3. What atoms make up the dry mass of plants?
Molecules in plants:
STARCH
FATS
GLUCOSE (SUGAR)
Image Credit: Craig Douglas, Michigan State University
Use Slides 3 and 4 to help students understand that the most important atom for plant biomass is carbon, and the other atoms make up much less of the plant.
CELLULOSE (FIBER)
PROTEIN
Atoms by dry mass: carbon (45%), oxygen (45%), hydrogen (6%), nitrogen (2%) and other elements (2%).

4. What atoms make up the dry mass of plants?
Use Slides 3 and 4 to help students understand that the most important atom for plant biomass is carbon, and the other atoms make up much less of the plant.
Atoms by dry mass: carbon (45%), oxygen (45%), hydrogen (6%), nitrogen (2%) and other elements (2%).

5. The Molecules in Water
Pure water contains only water molecules, but the water in soil is not pure.
What other molecules are in water?
Image Credit: Craig Douglas, Michigan State University
Use Slides 6 and 7 to discuss other molecules that are in the soil. Ask students to identify the atoms that are in these molecules. Ask students if they think that these molecules can make up the materials from which plants are made. Ask: do they have the right atoms?

6. Dissolved Minerals in Water
Water also contains dissolved minerals that are nutrients for plants. These minerals have different kinds of atoms, including:
Nitrogen
Phosphorous
Calcium
Potassium
AMMONIA
PHOSPHATE
CALCIUM
POTASSIUM
Image Credit: Craig Douglas, Michigan State University
Use Slides 6 and 7 to discuss other molecules that are in the soil. Ask students to identify the atoms that are in these molecules. Ask students if they think that these molecules can make up the materials from which plants are made. Ask: do they have the right atoms?

7. Does water contribute to plant dry mass?
Water does not have carbon atoms in it, so can’t account for the majority of the dry mass of a plant.
Although plants take up water, it doesn’t become part of a plant and evaporates when we dried the plants.
Image Credit: Craig Douglas, Michigan State University
Show students Slides 8 and 9 to tell students that only water and inorganic minerals enter the potato plant through its roots, and none of these molecules have carbon atoms, and that none of these materials are organic.
Use Slide 8 to explain to students that water is used by the plant, but doesn’t become part of cells and was dried out when the plants were dried.

8. Do soil minerals contribute to plant dry mass?
Soil minerals do not have carbon atoms in them, so they can’t account for the majority of the dry mass of a plant.
Soil minerals do become part of a plant, especially nitrogen in ammonia which is used to make amino acids.
Image Credit: Craig Douglas, Michigan State University
Use Slide 9 to explain to students that plants also take up ammonia, which is important for the plant to make amino acids. But the nitrogen in the ammonia only makes up a small part of the plant’s material (2%). Tell students that in this lesson, they focus on water and nitrogen as the main materials that enter through the roots.

9. Molecules that are gases in the air
Air is made of molecules that are gases, including:
Nitrogen (N2)
Oxygen (O2)
Carbon dioxide (CO2)
Oxygen O2
Water H2O
Image Credit: Craig Douglas, Michigan State University
Use Slide 11 to discuss other molecules that are in the air. Ask students to identify the atoms that are in these molecules. Ask students if they think that these molecules can make up the materials from which plants are made.
Carbon dioxide CO2
Nitrogen N2

10. Does air contribute to plant dry mass?
Carbon dioxide does have carbon atoms in it, and it accounts for the majority of the dry mass of a plant!
(Nitrogen (N2) doesn’t become part of a plant because the molecule is too difficult to break.)
Image Credit: Craig Douglas, Michigan State University
Show students Slides 12 to tell students carbon dioxide does have carbon atoms, and it is these molecules that account for the majority of the mass of a plant. The carbon dioxide also provides the oxygen atoms that make up plants. Ask students if they remember how that happens, and see if they can connect this idea to photosynthesis. Explain that plants cannot use nitrogen molecules (N2) in the air to make amino acids because N2 molecules take too much energy to break. (If they want to know more, you can explain the process of nitrogen fixation that occurs by microbes in the soil that result in the creation of ammonia.)

11. Does air contribute to plant dry mass?
Oxygen molecules do not have carbon atoms in it, but oxygen is still an important input to plants from the air. You’ll learn about this when you talk about cellular respiration.
Image Credit: Craig Douglas, Michigan State University
Use Slide 13 to explain that oxygen also enters the plant from the air. This doesn’t make up the materials in the plant, but is important for cellular respiration. All the cells in the plant need oxygen for this process.

12. What are the molecules that leave plants?
Think about what you know are the products of photosynthesis and cellular respiration.
Image Credit: Craig Douglas, Michigan State University
Ask students to also add their ideas about outputs from the plant, which are the products of photosynthesis and cellular respiration using Slide 14 and 15. (Nitrogen stays in the plant unless the plant drops its leaves or some of its roots die.)

13. What are the molecules that leave plants?
Carbon dioxide and water leave all cells of a plant after cellular respiration.
Oxygen leaves the leaves after photosynthesis.
Image Credit: Craig Douglas, Michigan State University
Ask students to also add their ideas about outputs from the plant, which are the products of photosynthesis and cellular respiration using Slide 14 and 15. (Nitrogen stays in the plant unless the plant drops its leaves or some of its roots die.)

14. Leaf: Movement of atoms during photosynthesis
After CO2 enters a leaf, it goes through photosynthesis to make sugar (glucose). Question: Where does the sugar go?
Image Credit: Craig Douglas, Michigan State University
Use Slide 16 to point out that carbon dioxide becomes sugar, which goes from the leaves to the rest of the plant. Also remind students that plants make amino acids using the nitrogen from ammonia. Ask students for their ideas about what the plant does with the sugar and with the amino acids. Ask students if potatoes are made of only sugar and amino acids, or are they made of other types of molecules as well? Tell students they will use some of these ideas to explain how large organic molecules that make up a potato are constructed using a potato poster in the next activity.

15. The Movement Question Where are atoms moving from?
Where are atoms moving to?
Image Credit: Craig Douglas, Michigan State University
Use Slide 2 to ask the Movement Question: Where are atoms moving from? Where are atoms moving to? Ask students for general responses to the Movement Question at the plant scale.

16. Which atoms and molecules move so that plants can grow through biosynthesis?
water
minerals
glucose
Image Credit: Craig Douglas, Michigan State University
Use Slide 3 to remind students of the molecules that are moving through the plant.

17. How do glucose water, and minerals move for a plant stem cell to grow?
Image Credit: Craig Douglas, Michigan State University
Use Slides 4 and 5 to overview which molecules are moving into the plant at a cellular scale. Tell students that it is this rearrangement of atoms inside of the plant cells that is the focus of this lesson: biosynthesis.

18. What happens inside the stem cell as it grows?
Chemical change
Image Credit: Craig Douglas, Michigan State University
Use Slides 4 and 5 to overview which molecules are moving into the plant at a cellular scale. Tell students that it is this rearrangement of atoms inside of the plant cells that is the focus of this lesson: biosynthesis.

19. How does a plant make the molecules that it is made of?
Biosynthesis
How does a plant make the molecules that it is made of?
Image Credit: Hannah Miller, Michigan State University
Explain to students using Slide 6 of the Lesson 4.4 Plant Biosynthesis Presentation that they know now where atoms come from that make up a potato, but they still haven’t learned how all of the molecules are made that make up the potato.

20. Organic molecules LARGE = Polymer STARCH GLUCOSE (SUGAR)
SMALL = Monomers
STARCH
Image Credit: Craig Douglas, Michigan State University
Use Slide 7 to remind students that carbohydrates like sugar and starch are made of monomers of glucose. Fats are made of monomers of glycerol and fatty acids, and proteins are made of monomers called amino acids. Explain to students that all of these are composed mainly of carbon, hydrogen, and oxygen and are rich with chemical energy and have C-C and C-H bonds. Have students identify the atoms in each molecule.
GLUCOSE (SUGAR)

21. Plants make their own organic molecules
The result of photosynthesis is glucose, then plants use the glucose to make other small organic molecules (MONOMERS)
Plus ammonia
AMINO ACID
Image Credit: Craig Douglas, Michigan State University
Use Slide 8 of the presentation to give an overview of the monomers that are used to make polymers. Point out that ammonia is also needed to supply the nitrogen atoms to synthesize proteins.
FATTY ACID
GLYCEROL
GLUCOSE (SUGAR)

22. Comparing organic molecules
Potatoes are made of starch, protein, fiber and fat
POLYMERS
FATS
(LIPID)
STARCH
Image Credit (molecules): Craig Douglas, Michigan State University
Image Credit (potato): Hannah Miller, Michigan State University
Use Slide 9 to remind students that a potato is made of polymers like starch, fiber and protein. Ask: how are those polymer molecules made?
PROTEIN
FIBER (CELLULOSE)