Part 1: Photosynthesis and Cellular Respiraiton Activity Guide (Day 12 and 13)
Purpose:
To provide students with a situation in which they can explore the relationship between photosynthesis and
respiration.
Part I Objectives:
Students will be able to:
 recognize the photosynthesis equation is basically the respiration equation “backwards.”
 realize that the very same carbon molecules that heterotrophs breathe out are the carbon molecules that
make up the backbone of the glucose molecule.
 write the equations for photosynthesis and respiration with coefficients and subscripts (study time is
required).
Part I Materials:
 three pieces of blue construction paper (cut each piece in half so you have six pieces on which to write
“C” to represent carbon [six molecules of carbon])
 six pieces of red construction paper (cut each piece in half so you have 12 pieces on which to write “H”
to represent hydrogen [12 molecules of hydrogen])
 nine pieces of green construction paper (cut each piece in half so you have 18 pieces on which to write
“O” to represent oxygen [18 molecules of oxygen])
 one piece of yellow construction paper (draw a sun to represent energy coming from the sun)
 one piece of white construction paper with a “+” on it
 one piece of white construction paper with an arrow to represent the yields sign in the equation
 posterboard with the equation for photosynthesis on one side and the equation for respiration on the
opposite side (to be held up so that students know where to position themselves)
 one piece of construction paper that reads “carbon dioxide”
 one piece of construction paper that reads “water”
 one piece of construction paper that reads “glucose”
 one piece of construction paper that reads “oxygen”
Preparation (teacher):
Students are not required to have background knowledge about photosynthesis and respiration to participate in
this activity. I give my students the following warm-up activity:
1. Write the equations for photosynthesis.
2. Write the equation for respiration.
3. Define: atom, element, molecule and compound.
Part I Procedure: (Kinesthetic activity)
Each student is given the role of a molecule of carbon,hydrogen, or oxygen. Depending on the size of your
class, some students may need to be assigned the role of two molecules of the same element. For example, you
may need to give one student two “H’s” instead of one “H.” If you have a large open area in your classroom,
you can conduct this part of the activity inside. Otherwise, you will need to plan to go outdoors, into the
hallway, or even to the school gymnasium or cafeteria.
Once you arrive at your destination, hold up the posterboard with the equation for photosynthesis facing the
students.
 First, instruct the students to position themselves so that they represent the reactants of the
photosynthesis equation. (Remember to assign a student to the role of “sun,” “+” and “yields”.)
 Once students have gotten into the correct positions give each group of molecules the name of the
substance that they represent (carbon dioxide or water).
 Next, have the students position themselves so that they represent the products of the photosynthesis
equation. Once the students have positioned themselves correctly give each group of molecules the
name of the substance they represent (glucose or oxygen). The idea is that students will realize that the
very same carbon atoms that make up carbon dioxide make up the backbone for the glucose molecule.
Now hold up the respiration equation.
 First have the students position themselves to represent the reactants for respiration. Again, when they
are correctly positioned, give the names of the substances that they represent to the groups of molecules
(oxygen and glucose).
 Next, have the students position themselves so that they represent the products of the respiration
equation. Once the students have positioned themselves, give the groups of molecules the names of the
substances they represent (carbon dioxide and water).
Safety:
No special safety equipment is necessary. Be aware that students may become particularly lively once they are
outside the classroom. A hand signal (for example, raising your right hand straight up) to let them know they
need to be still and quiet may be helpful.
Assessment: Exit
Ticket