Building an Oak Tree:Photosynthesis Notes I

7.5 Matter and energy. The student knows that interactions occur between matter and energy. The

student is expected to: 7.5 (A) recognize that radiant energy from the Sun is

transformed into chemical energy through the process of photosynthesis;

Create an entry in your science notebook:

Date Title Assignment Page10/5 Photosynthesis 1 Notes 1 18

Instructions• Your instructions and questions will be in bright blue text

boxes.

• With your group, you must complete the tasks required and record the answers to the 20 questions in your notes section (questions will be worth 5 points each)

• You do not have to answer in complete sentences unless told to do so. Follow instructions in each box carefully!

• You should have a set of blocks with three different colors at each lab table. There should be 16 of one color, 12 of another, and 6 of the third

• Were you absent? Get some legos or other blocks and do this at home!! You

just need some connecting blocks in three different colors!

Text boxes look like this!!

PHOTOSYNTHESISPHOTOSYNTHESIS

• WITHOUT IT, WE WOULD HAVE WITHOUT IT, WE WOULD HAVE

• - - NONO FOOD FOOD

• - - NONO FUEL FUEL

ANDAND

• - - NONO OXYGEN!!!! OXYGEN!!!!

1. True or False? Photosynthesis is essential to life as we know it

Photosynthesis in short

The process in which plants use energy from the sun and available nutrients to create food for

themselves

2. Why do plants go through photosynthesis?

From Seed to TreeFrom Seed to Tree• How does an acorn get enough mass to How does an acorn get enough mass to

grow into a large oak tree?grow into a large oak tree?

3. State your hypothesis about the above statement.

What are the essential ingredients What are the essential ingredients for Photosynthesis?for Photosynthesis?

Nope! not every plant needs soil, though most do!

4. Record the three essential ingredients for photosynthesis in your notes!

Photosynthesis as a

chemical reaction:Carbon Dioxide + Water React with the help of Sunlight and Chlorophyll Glucose + Oxygen

6CO2 + 6H2O Sunlight and Chlorophyll C6H12O6 + 6O2

5. Write down the chemical equation for photosynthesis

Today you will be constructing molecules and taking them

through the steps of photosynthesis!

Look at the different colored blocks on your lab table. You should have

18 Green blocks = Oxygen,

12 Red blocks = Hydrogen

6 Black blocks = Carbon.

Look at the chemical equation that you wrote down earlier. Using the numbers given to you, determine which element

Carbon (C) , which is Oxygen (O) and which is Hydrogen (H).

6. Identify each of your elements by color and number

Carbon Dioxide + Water

6CO2 + 6H2O

Each person in your group should construct one or two of each molecules. All together there should be 6 Carbon Dioxide molecules

and 6 water molecules.

7. Draw and label each of the molecules in your notebook. Title the drawing Reactants. They MUST be color coded!!

Let’s look at the stuff on the left of the arrow in the equation. These things are called “reactants” because they react with each other tomake something new.

The 6 before CO2 and H2O just refers to the need to have six of each molecules!

The Reactants

Your molecules should look Your molecules should look something like this (but square!)something like this (but square!)

C

O O

C

O O

C

O O

C

O OC

O O

C

O O Notice how carbon is in the center of CO2

And Oxygen is in the center of H2O. Fix your molecules if they are incorrect!

So… the stomata (little windows in the leaves of the plant) have taken in CO2 and the roots have

taken in H2O…

OHH

OHH

OHH O

HH

OHH

OHH Now, let’s recombine

some of these things.

8. How does carbon dioxide move into the plant?

Wait! Are the windows open?Wait! Are the windows open?Breaking apart the CO2 and H2O molecules takes energy.Recombining those bits, like Lego pieces, takes energy, too.Where does the energy come from?

Gee, I wonder.

And that’s why we write “sunlight” on top of the arrow. It’s not actuallya raw material that gets used up, and it’s not actually created by thereaction, either. It is the energy that facilitates the reaction! That’s why it’s on top of the arrow and not on either side of it.

9. Why do we have to make sure that the window is open?

Ok, now that we have some Ok, now that we have some energy….energy….

…the molecules are first broken apart into their separate elements, and are thenAble to recombine into new molecules!

C

O O

C

O O

C

O O

C

O O

C

O O

C

O O

OHH

OHH

OHH

OHH

OHHO

HH

C

OO

CO

OC

OO

CO

O

C

O

O

COO

OH

H

OH

H

O

H

HO

HH

O

HH

OH

H

Break your molecules back down into individual elements.

10. What enables the molecules to break down and recombine?

Products: What gets made?Products: What gets made?Now, let’s look at the right side of the arrow, called “products” in chemistry.These are the materials that are created from the chemical reaction.

6CO2 + 6H2O 6O2 + C6H12O6

(sunlight)

O

O

The first product is something the plant considers waste. Oxygen.Yeah, the same oxygen that you absolutely need to be able to survive.The plant gives off the oxygen to the atmosphere because O2 is a byproduct.

O

O

O

O

O

O

O

O

O

O

Plants USE our waste and then consider precious oxygen THEIR waste?

Weirdos.

Create six molecules of O2.. Make sure everyone is participating here!!

11. Draw and label one molecule of oxygen.

12. What are products in a chemical reaction?

And the Other Product?And the Other Product?

6CO2 + 6H2O 6O2 + C6H12O6

(sunlight) This complicated lookingmolecule is the whole reasonwhy the plant does photosynthesisin the first place. It is a sugar thatyour body needs and so does theplant. It’s called glucose!

C

O

H

C

C C

CC

O

O

O

O

O

H

HH

H

HH H

H

H

H

H

Create a molecule of glucose using the elements you have left. It does not have to look

just like this one, as long as it has the correct number of each

element!

13. Draw and label your glucose molecule

Is that the end???

• NO of course not! That would be too easy!!

• Plants use glucose for various functions, such as to fuel cellular respiration (a process that is essential to give energy to both plant and animal cells) or to combine into other macromolecules.

Have one member of your group go to the front and combine your glucose molecule with the other glucose molecules of the plant.

14. What do the combined molecules represent?

• Chains of glucose and maltose form cellulose. Cellulose is probably the single most abundant organic molecule in the biosphere. It Chains of glucose and maltose form cellulose. Cellulose is probably the single most abundant organic molecule in the biosphere. It is the major structural material of which plants are made. Wood is largely cellulose while cotton and paper are almost pure cellulose. is the major structural material of which plants are made. Wood is largely cellulose while cotton and paper are almost pure cellulose.

• Cellulose is a strong macromolecule (large molecule) and is the perfect material for building the cell walls of plants Cellulose is a strong macromolecule (large molecule) and is the perfect material for building the cell walls of plants

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Carbohydrates.html

15. What are the three different elements in cellulose?

16. How does this compare to glucose?

17. What is a macromolecule?

In conclusion..• Photosynthesis is a process that uses

sunlight and available sources of carbon, hydrogen and oxygen to create glucose.

• Glucose, in turn helps to build all of the other tissues of a plant.

• In short, a plant is 98.8% carbon, hydrogen and oxygen

18, 19, 20. look at your hypothesis in question #3. Write a conclusion.

So what is the remaining 1.2% ?So what is the remaining 1.2% ?Percentages of elements found in dried plant materialPercentages of elements found in dried plant material

H 45.6 H 45.6

C 30.4 98.8C 30.4 98.8

O 22.8 O 22.8 N 0.76 N 0.76

K 0.19 K 0.19

Ca 0.09 Ca 0.09

Mg 0.06 Mg 0.06

P 0.05 P 0.05

S 0.02 S 0.02

Cl 0.002 Cl 0.002

B 0.001 B 0.001

Fe 0.001 Fe 0.001

Mn 0.0008 Mn 0.0008

Zn 0.0002 Zn 0.0002

Cu 0.00008 Cu 0.00008

Mo 0.0000007Mo 0.0000007

The remaining 1.2 % are minerals from the soil. Plant typically absorb these minerals through their roots along with water.

Please note that none of these elements are present in glucose, the plant’s food source!

21. Do plants absorb food through their roots??

22-25. Draw a pie graph that represents the different elements found in plants. You may group the 1.2% together as “trace elements”