FREE ESSAY ON CELLULAR RESPIRATION LAB

CELLULAR RESPIRATION LAB

Introduction
This lab was done to determine the relationship of gas production to respiration rate.
Justin Pyka and I did the lab on December 12th, 2000 in Mr. Myers' room. The lab was done
with dormant pea seeds and germinating pea seeds. It was done to test the effect of
temperature on the rate of cellular respiration in ungerminated versus germinating seeds.
We had to determine the change in gas volume in respirometers. This was done to determine
how much oxygen was consumed during the experiment. The respirometers contained either
germinating, or non-germinating pea seeds. I think that the germinating seeds will have a
higher oxygen consumption rate in a room temperature water bath than the non-germinating
seeds. My reason for this hypothesis is that a dormant seed would not have to go through
respiration because it is not a plant yet. A germinating seed would consume more oxygen
because it is growing, and therefore would need to consume oxygen by going through the
process of cellular respiration.
Methods and Materials
Materials:
Glass Vials
1 mL Glass Pipette Tubes
Rubber Stoppers
264 Germinating Pea Seeds
264 Dried Pea Seeds
100 mL Graduated Cylinder
Glass Beads
Absorbent Cotton
Solid KOH
Dry Cotton
25 Degree C Distilled Water Bath
10 Degree C Distilled Water Bath
Red Indicator (Safrin)
Syringe With Needle on End
Rubber Stoppers
Methods:
See lab handout for methods of completing the experiment and recording the results.
Note: Two tests were done for each step.
Results
See graphs for interpretation of results.
In the room temperature water bath, the glass beads, and the dry pea seeds and glass
beads consumed the least amount of oxygen (see chart 1). The germinating pea seeds
consumed the most oxygen. They consumed almost three times as much oxygen as the glass
beads alone, and the glass beads and dry pea seeds.
According to my results, the vials containing the glass beads in the 10-degree C water
bath consumed large amounts of oxygen (see chart 2). The vials containing the dry seeds
and glass beads had the same result. I think that this is because the gas in the vials
cooled, and when it cooled, it took up less space in the vial, therefore pulling the
indicator down the respirometer tube, which would make it look like the contents in the
vials consumed large amounts of oxygen.
The germinating seeds consumed almost no oxygen throughout the experiment in the
10-degree C water bath. I think that this is because when an organism cools down, all of
its cellular functions slow down. Which means that the germinating seeds would slow down
their respiration rates because of the colder temperature. The indicator stayed at about
the same spot in the respirometer tube. That means that the germinating seeds were
producing some gasses to offset the reduction in the space taken up by the gas in the
vials caused by the cooler temperature.
Conclusion
After completing this experiment, I have come to the conclusion that a germinating seed
of a plant consumes more oxygen than a dry seed of a plant. When the germinating seed is
cooled down however, the rate of oxygen consumption is reduced drastically because all of
the cellular processes are slowed down from the cooler surroundings.
I think that my hypothesis was correct because my results from the experiment show that
the vials containing the germinating seeds consumed more oxygen in the room temperature
water bath than the other vials.
This lab was a good representation of what effects temperature has on cellular processes
because it showed that respiration slowed down when the temperature was reduced, and
respiration increased when the temperature increased.