CEP – Cell Energy Processes Lab
1.
Pre-lab:
What are some basic needs of plants?
2.
What are some basic needs of animals?
3.
How are plants and animals dependent on each other?
1.
Part one: Photosynthesis
On the leaf, draw an arrow with the reactants going in, and then the products going out.
You have the raw atoms for photosynthesis, which you will assemble the reactants.
Atom
Number of Pieces
Color of Pieces
Oxygen
18
Hydrogen
12
Carbon
6
Make a water molecule, H2O, by putting 2 hydrogen atoms and 1 oxygen atom together. Make a carbon dioxide
molecule, CO2, by putting 1 carbon atom and 2 oxygen atoms together. Continue to make molecules until all of the
colored pieces are used. Make a colored diagram of your H2O and CO2 molecules, and indicate the atoms within the
molecule with a label.
Water
Carbon Dioxide
2.
How many molecules of water were you able to make? __________________
3.
How many molecules of carbon dioxide were you able to make? __________
When the sun is present, it provides energy to these reactants and a chemical reaction takes place. To provide the
energy that this reaction needs you are going to act as the sun. Carefully shake your paper to mix up the colored
pieces. Make sure that you keep all of the pieces on the paper. Use the same colored pieces that you used to
construct your reactants to make a simple sugar molecule called glucose (C6H12O6), by putting 6 carbons, 12
hydrogen’s and 6 oxygen’s together on the glucose page. You should have colored pieces left over. Put these
oxygen atoms together in pairs (making O2).
a.
Using your colored pencils, make a diagram (in color) of all of the glucose and oxygen molecules.
Glucose (sugar)
Oxygen
b.
c.
4.
How many glucose molecules did you make? ________________
How many oxygen molecules did you make? _______________
Write the total number of atoms you needed in the reactants and products for photosynthesis.
atom
Number needed for reactants
Number needed for products
Oxygen
Hydrogen
Carbon
5. What do you notice about the number of atoms in the reactants and products?
6.
When you shook up the carbon dioxide and water molecules to make the glucose and oxygen molecules you added
energy to break molecular bonds. In nature, where does this energy come from?
7. During photosynthesis, light energy is changed to stored energy. In which product is the energy stored?
8. Photosynthesis can take place only in certain cells. What do all cells in which photosynthesis takes place have in
common?
9. An astronaut is about to embark on a space mission in which he or she will be confined to the cabin of their space
ship for a long time. Why might an astronaut wish to create a greenhouse full of plants within his or her space ship?
Part B: Cell respiration
Within the mitochondria of plant and animal cells, the products from photosynthesis are used, and glucose is
combined with oxygen and energy is released. When the bonds between the atoms are broken the atoms rearrange,
forming CO2 and H2O.
1. On the mitochondria, draw an arrow with the reactants going in, and another arrow with the products leaving.
2. Make a water molecule, H2O by putting 2 hydrogen atoms and 1 oxygen atom together.
Draw the compound below.
3.
4.
Make a carbon dioxide molecule, CO2 by putting 1 carbon atom and 2 oxygen atoms together. Draw the
compound below.
Using your colored pencils, make a diagram of all of the products from cellular respiration.
Carbon Dioxide
Water
5. How many carbon dioxide molecules did you make? ______________
6. How many water molecules did you make? ______________________
7. Write the total number of atoms you needed in the reactants and products for cell respiration
atom
Number needed for reactants
Number needed for products
Oxygen
Hydrogen
Carbon
8. What do you notice about the number of atoms in the reactants and products?
9. What happens during cellular respiration?
10. How do the reactants and products of respiration relate to what we (humans) take in and give off?
11. How are plants and humans dependent on one another?
12. A seventh grader was running in gym class and noticed that they would breathe heavier (and take in more
oxygen) when they were active, as opposed to when they were sitting still in other classes. Why would the seventh
grader need more oxygen when they were active?