Cell Respiration

(Originally on my website)

Cell Respiration Lab

Abstract: In this lab we tested cell respiration by mixing yeast with sugar, water, and salt. We tested to see if cell respiration was affected by the temperature, and we found out that as the temperature rises the amount of cell respiration increases. We did this by placing four test tubes in different temperatures and measuring the amount of CO2 produced. 

Introduction:

       The question we wanted to answer in this lab was, how does the temperature effect cell respiration? Cell respiration has three parts known as glycolysis, the citric cycle/ Kreb's cycle, and oxidative phosphorylation. During these steps mitochondria transform fructose, galactose, or glucose into energy, or ATP. The formula equation for this is C6H12O6 + 6O2 → 6CO2 + 6H2O + 36-38 ATP. We wanted to test to see if this process was affected by the temperature it takes place in. We know that the hotter things are the more molecular motion they possess. 

Hypothesis: The higher the temperature the more CO2 should be produced, because it will possess more molecular motion.

Materials:

• Four test tubes
• Yeast
• Water
• Sugar
• Salt
• Syringes with a plug to fill the test tube
• Room temperature water
• Dry hot bath
• Ice bath
• Freezer

Procedure: 

1. Label your test tubes
2. Measure your salt, sugar, water, and yeast for each test tube
3. Mix all of your test tubes at the same time
4. Make sure all of your stoppers are tightly placed in each test tube
5. Monitor the cell respiration for 5 minutes to get a basis
6. Place each test tube in the different temperatures
7. Record the CO2 every two minutes for 10 minutes

Results:

Temperatures	2 mins	4 mins	6 mins	8 mins	10 mins
Control (Room Temp.)	2	2.8	3	3	3
0 degrees C	2.2	2.6	2.8	2.8	3
20 degrees C	2.2	3.2	2.8	4	4.6
50 degrees C	2.2	4	6	9.4	+12

Conclusion: In this lab we have proven that as the temperature increased the amount of CO2 increased. This proves our hypothesis correct. The rate and amount of cell respiration were directly affected by the temperature it was surrounded in. The molecular motion was sped faster in warmer temperatures, therefore the rate and amount of cell respiration increased as the temperature increased. There were many errors that could have taken place throughout this experiment. I think the most likely error would be if the stopper wasn't fully inserted, so the CO2 produced could leak into the open air disturbing out data. Also the timing with two people trying to take 4 marks at the same time became very difficult and could slightly skew our data. Overall I think we did have a few faults in the experiment, but we got the general data and understanding of the experiment. 

Transpiration Lab

Plant	Normal (mL)	With Fan (mL)	With Heater (mL)	With Lamp (mL)
English Ivy	1.8	5.1	3.2	2.1
Weeping fig	3.3	6.1	4.9	2.5
Devils Ivy	2.9	4.6	4.1	3.0
Arrowhead	3.6	7.5	6.6	4.0
Dieffenbachia	4.1	7.7	6.0	3.9
Geranium	1.2	4.7	5.8	2.4
Coleus	0.9	6.0	3.9	3.0
Zebra Plant	4.2	7.6	6.1	3.2
Rubber Plant	4.9	8.4	6.8	4.3

1) Transpiration is the process in which plants acquire nutrients from the air and lose their moisture.
2) The control of this lab would be the amount of transpiration that took place at 21°C after an hour.
3) We tested wind, light, and heat. All which can naturally take place in any environment in which the plants live. Not all plant transpiration was positively affected by the different environmental elements.
4) Wind typically had the largest effect on most plants transpiration levels. I believe it is because with wind more air reaches the plants leaves allowing it to obtain more nutrients.
5) The rubber plant had the highest amount of transpiration followed by the dieffenbachia. Plants have different levels of transpiration based upon their leaves and how much the nutrients the leaves are able to obtain.
6) I believe if the leaves were covered in jelly they would obtain nutrients faster because of the stickiness of the jelly, therefore the transpiration would be larger.
7) It is of large value for the plants survival helping them obtain the proper nutrients they need to survive.