Name:________________________________ Date: ________________ Class: __________ #: __________
Pre lab Questions:
1. Complete the table below. Use the provided equations to write out the common names of the molecules
that are found in the reactants and products. For example, if NaCl were one of the molecules in the equation,
you would write out Sodium Chloride (or salt) in the blank. Refer to the background information if you forgot
the common names of any of the molecules.
Photosynthesis: 6 CO2 + 6 H2O → C6H12O6 + 6 O2
Respiration: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
Reactants (ingredients)
Products (given off)
Photosynthesis
Respiration
2. How do the reactants and products for photosynthesis and respiration compare?
Procedure Questions:
1. Why should you not need to use any more disks after you have placed the remaining disks in the bag?
2. Draw a colored picture of your disk representation of the photosynthesis reaction.
*Be sure to separate products and reactants with a yield sign.
3. Compare the number of each type of atom in the reactants to the number of each type of atom in the
product. Did you use any more or any less of an atom?
Are your reactants and products the same? Describe how the arrangements of atoms have changed.
4. Draw a colored picture of your disk representation of the cellular respiration reaction.
*Be sure to separate products and reactants with a yield sign.
5. Complete the table below to compare the total number of atoms:
Photosynthesis
Reactants
Products
Reactants
Carbon
Oxygen
Hydrogen
Respiration
Products
Conclusion Questions:
1. Describe the pattern between how many atoms are in the reactants and how many are in the products?
Describe the significance of the pattern
2. What is the law of conservation of matter?
3. How was the law of conservation of matter demonstrated in this lab?
4. Why are the products of the photosynthesis reaction necessary for life on earth?
5. Describe the relationship between the products of cellular respiration and our respiratory system?
Pre Lab
Questions
Procedure
Questions
Conclusion
Questions
3
The table is professional in
appearance and is completed
thoroughly and accurately with
no errors.
The reactants and products for
photosynthesis and respiration
are compared accurately with
detail.
There is a thorough
understanding of the procedure.
All tasks are completed
accurately. Explanations are
detailed and correct.
2
The table is neat in appearance
and is completed thoroughly
with few errors.
The reactants and products for
photosynthesis and respiration
are compared correctly with
little detail.
Conclusion is thorough and uses
specific evidence from
background text and data.
Conclusion is general and uses
some evidence from background
text and data.
Participation
I often contributed good ideas that were
relevant to the topic and task. I came to
meetings prepared. I did my share of the work.
Working with Others
I often compromised and cooperated. I did take
initiative when needed and/or listened and
respected the ideas of others.
Product
My part of the task is complete and accurate.
My work was submitted on time.
Understanding Content
I can speak about the topic and group work
knowledgeably. I can sum-up the lesson.
There is an understanding of the
procedure. Most tasks are
completed accurately.
Explanations are correct but lack
detail.
1
The table is not neat in
appearance and is either
incomplete or contains several
errors.
The reactants and products for
photosynthesis and respiration
are compared however there are
errors and missing details.
There is a partial understanding
of the procedure. Few tasks are
completed accurately.
Explanations are lacking detail.
Conclusion is general and uses
some evidence from background
text or data.
4
3
2
1
I seldom contributed good ideas. Sometimes I was
talking off-task. I did not come to meetings prepared.
I did not do my share of the work.
4
3
2
1
I seldom compromised and cooperated. I did not take
initiative when needed and/or did not listen and
respect the ideas of others.
4
3
2
1
I did not complete my part of the task. The
information I presented was inaccurate and/or not
done correctly. It was not completed on time.
4
3
2
1
I do not understand what I did in my group. I did not
ask or answer questions. I cannot sum-up the lesson.
Procedure:
1. Use the colored disks to show the reactants of photosynthesis. Arrange the disks so they represent the
molecules on the reactants side. Remember that molecules are bonded together.
Have your teacher check your model for accuracy.
2. After your teacher has approved your model, you may put all the remaining disks back in the bag. The
number of disks you are using now should be all that you need.
3. Procedure Question #1: Why should you not need to use any more disks after you have placed the
remaining disks in the bag?
4. Procedure Question #2a: Draw a colored picture of your disk representation of the photosynthesis
reactants. * Be sure to leave space for drawing the products of the reaction.
5. Use the same disks to show the products of photosynthesis. Have your teacher check your model for
accuracy.
6. Procedure Question #2b: After your teacher has approved your model, draw a colored picture of your disk
representation of the photosynthesis products (next to the reactants). *Be sure to separate with a yield
sign.
7. Procedure Question #3: Compare the number of each type of atom in the reactants to the number of each
type of atom in the product. Did you use any more or any less of an atom?
Are your reactants and products the same? Describe how the arrangements of atoms have changed.
8. Use the same disks to determine if the same atoms used during photosynthesis can be used for
respiration.
9. Procedure Question #4: Draw a colored picture of your disk representation of the cellular respiration
reaction (both the reactants and the products). *Be sure to separate reactants from products with a yield
sign.
10. Procedure Question #5: Complete a table to compare the total number of atoms in the reactions for
photosynthesis and cellular respiration.
During this lab you will be using disks to represent the molecules found in
photosynthesis and respiration reactions. While studying these two reactions you
will encounter the following molecules:
CO2 (carbon dioxide), H2O (water), C6H12O6 (glucose), and O2 (oxygen).
As you know, photosynthesis is the process in which plants (also called autotrophs
or producers) use water and the radiant energy of the sun to create simple sugar
(glucose) as a food source and oxygen as products of the reaction.
Cellular respiration is the process that takes place in the cells of organisms in
which chemical reactions turn sugar (glucose) that we get from food along with
oxygen into adenosine triphosphate (ATP). For the purposes of this lab, we will
refer to ATP as “energy.” You can think of it as a kind of chemical battery that
allows our body to store energy and rerelease it when needed.
The law of conservation of matter is a fundamental principle of science that states
that matter is neither created nor destroyed; it simply changes form. You will see
that during photosynthesis and respiration, the number of atoms in the reactants
(the “ingredients” on the left side of the formula) will equal the atoms in the
products (the things that are given off after the “ingredients” undergo a chemical
reaction), on the right side of the formula. You will also learn the molecules that
make up the reactants and products for photosynthesis and respiration.