CELL RESPIRATION AP LAB
Materials:
Peas (germinating, non-germinating, split)
Beads
1 mL glass pipets
Forceps
15% KOH solution
Absorbent cotton
60 mL syringes
Plastic tubes
Non-absorbent cotton
Procedure:
1. Seed/Bead Preparation:
 For Set-Up A, put 25 mL of water into the 50 mL plastic graduated tube. Drop in 25 germinating peas. Determine
the volume of water that has been displaced, which is equivalent to the volume of peas. Record the volume of the
germinating peas on the worksheet. Remove the peas and place them on a paper towel.
 For Set-Up B, repeat the procedure listed for A, but add 25 dry, dormant peas. Add enough glass beads to equal
the volume of the germinating peas. Remove the dormant peas and beads, and place them on a paper towel.
 For Set-Up C, repeat the procedure listed for A, but add 25 germinating, split peas. Add enough glass beads to
equal the volume of the germinating peas. Remove the dormant peas and beads, and place them on a paper towel
 For Set-Up D, repeat the procedure listed for A, but do not add any peas. Add enough glass beads to equal the
volume of the germinating peas. Remove the beads and place them on a paper towel.
2. Preparing the Syringes:
 Place the appropriate peas/beads into the barrel of each syringe according to the instructions below:
Place the germinating peas in Set-Up A.
Place the dry peas and beads in Set-Up B.
Place the germinating, split peas and beads in Set-Up C.
Place the beads in Set-Up D.
 Place a small a small wad of non-absorbent cotton on top of the peas/beads in each syringe.
 Place a small amount of absorbent cotton on top of the non-absorbent cotton. Use approximately the same amount
of absorbent cotton as compared to the non-absorbent cotton. It is important that the cotton be the same for all four
set-ups.
 Saturate the cotton with KOH solution (~ 20 drops). Add the same number of drops to the absorbent cotton ball in
each set-up.
 Insert the plunger in the syringe barrel pushing it to the 60mL mark.
 Attach the small piece of plastic tubing to the end of each of the syringes.
 Carefully push the glass pipette into the plastic tubing so that an airtight seal is formed. If there are leaks in the
respirometer, you will have to start over.
3. Place the syringes in a location where they will not be disturbed.
4. Carefully add 5-6 drops of food coloring to the tip of each pipet. The food coloring must reach the markings on the side of the
pipet so that volume can be read.
5. Allow the respirometers to equilibrate for 2-3 minutes.
6. Record the initial volume reading on the pipet scale to the nearest 0.01 mL. This represents T = 0 min.
7. Continue monitoring the respirometers, recording the volume reading every 5 minutes for a total of 15 minutes. You should
have 4 readings.
Clean-Up:
1. Separate the plungers and syringes carefully.
2. Discard the contents of Set-Ups B, C, and D.
3. For Set-Up A, we will be planting our pea seeds and having a contest to determine which table grows the healthiest pea plant.
This contest will last through our unit on Mendelian Genetics! 
4. Label a Petri dish with your period number-table number. Line the dish with damp paper towel. Place the germinating seeds
on the paper towel. Then cover with another damp paper towel. Please note: Although it is important to provide a moist
environment, the seeds will die if they are incubating in standing water.
5. Clean and dry all lab equipment.
6. Wipe down the table top. Remove safety equipment. Wash your hands.
Write-Up
 Due Friday, 11/15
 Abstract
o 200-word maximum
 Data
o Data Table
o Graph
 Use corrected volumes for each set-up
 Line of Best Fit for each data set