Cellular Respiration lab

Cellular Respiration
Problem:
We are attempting to see how having a germinated specimen vs. ungerminated vs. non-living affects the rate of oxygen consumption. As time goes on throughout the lab we will be able to see the different rates of respiration that each of the samples will have.
Hypothesis:
If three different samples are taken and have the same mass but, have different compositions of living/non-living organisms, then the samples that have been germinated and have the highest composition of living organisms will have the highest rate of respiration and the samples that contain no living organisms will have the least amount of respiration.
Materials:

Tub of ice water  

3 vials

10 germinated peas

Ungerminated peas

Glass beads

Scotch tape

Thermometer 

KOH (Potassium Hydroxide)

3 Cotton balls

3 Non-absorbent Rayon

Food coloring

White paper

Timer

3 Pipettes

Dropper

Tweezers

Procedure:

1. Soak 3 cotton balls in KOH (Caution KOH is corrosive, use gloves and goggles) *Control

2. Use Tweezers to place KOH into each of the 3 vials. 

3. Place non-absorbent Rayon in each of three vials. *Control
4. Fill a glass vial with 10 germinating peas. *Independent Variable
5. Fill the 2nd glass vial with 10 ungerminated peas. *Independent Variable
6. Place glass beads in 2nd vial until it is of equal volume to first vial.
7. Place an equal volume to the 1st vial of glass beads into 3rd vial. *Independent Variable
8. Place stopper and pipette onto each vial.

Courtesy:http://www.biologycorner.com/worksheets/cellular_respiration_AP_Lab5.html

9. Place scotch tape across tub.
10. Place white paper into cold water.
11. Place thermometer in water.
12. Rest each pipette of the vials into the scotch tape. See below.

Courtesy:http://www.biologycorner.com/worksheets/cellular_respiration_AP_Lab5.html

13. Wait five minutes to allow beads and peas to adjust to water.
14. Remove Scotch tape.
15. Place drop of food coloring onto each opening of pipette using a dropper.
16. Submerge pipettes into ice water and remove tape.
17. Measure where air bubble is on pipette. *Dependent Variable (oxygen consumption).
18. record every two minutes
19. After ten minutes stop recording.

Results

	0 Min	2 Min	4 Min	6 Min	8 Min	10 Min
Vial 1	8 Ml	7.3 Ml	7 Ml	6.6 Ml	6.2 Ml	6 Ml
Vial 2	7.5 Ml	7.4 Ml	7.4 Ml	7.4 Ml	7.3 Ml	7.3 Ml
Vial 3	7.2 Ml	7.3 Ml	7.3 Ml	7.3 Ml	7.2 Ml	7.2 Ml

Discussion:

This lab demonstrates how organisms use up oxygen at different rates and that non-living organisms do not use oxygen. This allowed me to develop a deeper understanding of respiration because i was able to actually see it in action. 

It turns out that my original thought was correct that the germinating peas would require the most oxygen because they are trying to grow. I was also correct in my guess that the glass beads a non-living thing would not require much oxygen if any at all. 

Our group encountered a few issues that probably effected the result of the experiment. For example, the vials once place are supposed to be left undisturbed. we had several occasions where the vials would be disturbed for various reasons. this caused more oxygen to seep out of the vials. Obviously, this would skew our results. Also, if you look at our bead vial results you will notice that the oxygen fluctuated up and down. theoretically there should have been no change however, the was an obvious fluctuation even if it was just about a tenth of a mL. This was probably caused by either a lack of precision in making our measurements or there was an actual fluctuation due to movement of the vials. in order to prevent this in the future i think I would not let the tub be on a table i would place it on a more sturdy table and keep certain individuals away from it to reduce the amount of interaction near the vials. It would also be nice if we had maybe found a way to construct holders to ensure they remained still.

All in all the experiment had i's flaws but the results were close enough that we could still grasp the concept of what it was trying to teach us.