Project Lab Report

Plant Physiology Project-Cell Respiration (Method 1–CO2 and O2)

Cell respiration refers to the process of converting the chemical energy of organic molecules into a form immediately usable by organisms. Glucose may be oxidized completely if enough oxygen is available according to the following equation:

C6H12O6 + 6O2 (g) (6 H2O + 6 CO2 (g) + energy

All organisms, including plants and animals, oxidize glucose for energy. Often, this energy is used to convert ADP and phosphate into ATP. This respiration is a multi-reaction procedure. CO2 is the product of cellular respiration and oxygen is utilized during cellular respiration. To measure the rate of respiration we can measure the oxygen consumption and carbon dioxide release.

Peas undergo cell respiration during germination. Do peas undergo cell respiration before germination? Using your collected data, you will be able to answer this question regarding respiration rate of germinated peas and non-germinated (dead) peas.

Using the CO2 and O2 Gas Sensors, you will monitor the carbon dioxide produced and the oxygen consumed by different specimens during cell respiration.

OBJECTIVES

The rationale of this experiment is to determine the relative rates of cellular respiration among germinated and non-germinated peas, cold and room temperature peas, and insects. This can be determined by measuring the amount of oxygen consumed and the amount of carbon dioxide that is released during a given amount of time.

In each specimen-we want to observe the changes in the O2 (ppm/sec) from the beginning to the end of the experimental set up-if we observe decline in the total amount of O2 registered in the lab quest (so more O2 at the beginning of the experiment and less O2 at the end of the experiment) the organism in the bio chamber must be respiring-because it is utilizing the O2. Similarly, we also want to observe the changes in the CO2 (ppm/sec) from the beginning to the end of the experimental set up -if there is increase in CO2 registered in the lab quest (so less CO2 at the beginning of the experiment and more CO2 at the end of the experiment) - the organism in the bio chamber must be respiring-because it is exhaling the CO2.

Additionally, we want to investigate how manipulating independent variable changes the dependent variable. Hence, identify independent variable, dependent variable, constant and replicates for each experiment (Review Chapter 1 in Lab Manual).

BUILD YOUR OWN HYPOTHESIS:

Formulated hypothesis is an educated guess that explains a phenomenon or answers a scientific question.

In case of germinated peas and non-germinated (dead) peas- which specimen would respire more? Which specimen will have released more CO2 and used up more O2 in the bio chamber during the experimental set up?

In case of germinated peas in room temperature and cold temperature - Will there be difference in respiration because of the difference in temperature? Which specimen would respire more? Which specimen will have released more CO2 and used up more O2 in the bio chamber during the experimental set up?

In case of germinated peas and insects- which specimen would respire more? Which specimen will have released more CO2 and used up more O2 in the bio chamber during the experimental set up? Fun fact- insects move and peas do not- do you think this will affect the rate of respiration between the specimens?

In this experiment, you will

· Use an O2 Gas Sensor to measure concentrations of oxygen gas.

· Use a CO2 Gas Sensor to measure concentrations of carbon dioxide gas.

· Study the effect of temperature on cell respiration.

In this experimental set up we are trying to see the difference in rates of respiration for

1. Germinated peas and non-germinated

2. Germinated peas in room temperature, and cold temperature.

3. Germinated peas and Insects.

Figure 1

MATERIALS

LabQuest	BioChamber 250
LabQuest App	Ice cubes
Vernier CO2 Gas Sensor	Two 100 mL beakers
Vernier O2 Gas Sensor	Thermometer
25 germinated peas and other specimens	Logger Pro (optional)

PROCEDURE/Method

1. Turn on the lab quest and calibrate the screen.

2. Choose New from the File menu. If you have older sensors that do not auto-ID, manually set up the sensors. If your CO2 Gas Sensor has a switch, set it to the Low (0–10,000 ppm) setting.

3. Do not try to connect to WIFI with the lab quest.

4. Measure the room temperature using a thermometer and record it in Table 1.

5. Obtain 25 germinated peas (or specimen provided in the lab) and blot them dry between two pieces of paper towel.

6. Place the germinated peas into the respiration Bio Chamber 250.

7. Connect the O2 Gas Sensor and the CO2 Gas Sensor to LabQuest.

8. Insert the Gas Sensors into the Bio Chamber 250 as shown in Figure 1. Insert the sensor snugly. The O2 Gas Sensor should remain vertical throughout the experiment. The CO2 Gas Sensor is horizontal in this experimental set up.

9. Make sure the units for CO2 and O2 gases are same (ppm).

10. Wait two minutes, to let the setting stabilize-then start data collection.

11. Data is collected for the amounts of CO2 and O2 gas in the Bio Chamber for duration of time of the experiment (See Tables 1A-C)

12. Do not touch or move the Bio Chamber/Lab Quest set up during data collection otherwise the data will be disturbed, and the graph will be jerky.

13. Record the data in different time intervals in the tables (1A-C) given below for each specimen.

14. When data collection has finished, remove the sensors from the respiration chamber. Take the specimens (e.g. peas) out.

15. Thoroughly dry the inside of the respiration chamber with a paper towel and store the Gas Sensors properly; O2 Sensor vertically and CO2 Sensor horizontally

16. Repeat Steps 5–14-substituting the germinated peas with other specimens provided (e.g. non-germinated peas etc)

17. One you have collected all the data-put the collected data in Excel sheet in tabular form. (check out the Plant Physiology -Cellular Respiration Data.XLS document in Canvas for the data)

DATA

Table 1
Condition	Temperature (°C)
Room

Table 1A
	O2 Rate of respiration (ppm/s)	CO2 Rate of respiration (ppm/s)
Germinated Peas	0 min 3 min 6 min 9 min 12 min	0 min 3 min 6 min 9 min 12 min
Non-germinated Peas	0 min 3 min 6 min 9 min 12 min	0 min 3 min 6 min 9 min 12 min

Table 1B
	O2 Rate of respiration (ppm/s)	CO2 Rate of respiration (ppm/s)
Germinated Peas, room temperature	0 min 3 min 6 min 9 min 12 min	0 min 3 min 6 min 9 min 12 min
Germinated Peas, cool temperature	0 min 3 min 6 min 9 min 12 min	0 min 3 min 6 min 9 min 12 min
Table 1C
	O2 Rate of respiration (ppm/s)	CO2 Rate of respiration (ppm/s)
Germinated Peas	0 min 3 min 6 min 9 min 12 min	0 min 3 min 6 min 9 min 12 min
Insects	0 min 3 min 6 min 9 min 12 min	0 min 3 min 6 min 9 min 12 min

ReSULT:

1. In the result, look at the data in Table (1A-C) and rearrange the data in the following tables-2(A-B), 3(A-B), 4 (A-B) -check out the Plant Physiology -Cellular Respiration Data.XLS document in Canvas for the data.

2. In MS Excel- make Line Graphs from the Tables - 2(A-B), 3(A-B), 4 (A-B)- Do Not Forget to Label the Axes. To get the axis labeling correct you need to know which variable (independent or dependent?) goes to the x-axis and which variable (independent or dependent?) goes to the y-axis.

Comparing Different Respiratory Gases in Different Specimens
	Table 2A
	Germinated Peas	Non-Germinated Peas
Time Interval (min)	O2 (ppm/s)	O2 (ppm/s)
0
3
6
9
12
	Table 2B
	Germinated Peas	Non-Germinated Peas
Time Interval (min)	CO2 (ppm/s)	CO2 (ppm/s)
0
3
6
9
12
	Table 3A
	Germinated Peas in Room Temperature	Germinated Peas in Cool Temperature
Time Interval (min)	O2 (ppm/s)	O2 (ppm/s)
0
3
6
9
12
	Table 3B
	Germinated Peas in Room Temperature	Germinated Peas in Cool Temperature
Time Interval (min)	CO2 (ppm/s)	CO2 (ppm/s)
0
3
6
9
12
	Table 4A
	Germinated Peas	Beetles
Time Interval (min)	O2 (ppm/s)	O2 (ppm/s)
0
3
6
9
12
	Table 4B
	Germinated Peas	Beetles
Time Interval (Min)	CO2 (ppm/s)	CO2 (ppm/s)
0
3
6
9
12

DISCUSSION:

1. From the graphical and tabular data in the result section we are trying to determine the differences in the rate of respiration between specimens by observing the changes in the amounts of O2 and CO2 in each of the experimental set up.

2. Begin with explaining the independent variable, dependent variable, constant and replicates for each experiment.

3. A. For Example- In Table and Graph 2A -Do the O2 (ppm/s) increase/decrease/remain the same in Germinated peas (between 0 minutes and 12 minutes)-if so why? (Hint- revisit the objectives in the beginning of the experiment)

B. Do the O2 (ppm/s) increase/decrease/remain the same (between 0 minutes and 12 minutes) in Non-Germinated peas-if so why?

C. In Table and Graph 2B- Do the CO2 (ppm/s) increase/decrease/remain the same (between 0 minutes and 12 minutes) in Germinated peas-if so why? (Hint- revisit the objectives in the beginning of the experiment)

D. Do the CO2 (ppm/s) increase/decrease/remain the same (between 0 minutes and 12 minutes) in Non-Germinated peas-if so why?

E. How does the line in the graph vary (flat/moving upwards/downwards) between the two specimens- what does that tell you about the respiration rates between these two specimens?

4. Do the same for Table/Graph 3(A & B) and 4(A&B).

5. When you observe these graphs what does it reflect on the respiration between the two specimens? Which specimens do you think are respiring? Which ones are not respiring? Which ones are respiring more relative to other? Do you think the temperature has any significant effect on respiration rate? Does the respiration rate vary between seeds and insect-Explain how?

Conclusion:

In conclusion, what did you learn from this experiment? Does your data support or reject the hypothesis you formulated at the beginning of the experiment?

IMPOrtant:

Please read the Research Project Lab Report guidelines when you write a lab report based on this experiment. Follow the guideline to further streamline and strengthen your Research Project-Plant Physiology-Cell Respiration lab report.

Also read primary literatures (peer reviewed research papers) for more information on Respiration, rates of respiration in different specimens, effects of temperature etc on respiration-these can be your reference material.

MORE THOUGHT Questions

1. Do you have evidence that cell respiration occurred in peas? Explain.

2. What is the effect of germination on the rate of cell respiration in peas?

3. What is the effect of temperature on the rate of cell respiration in peas?

4. Why do germinating peas undergo cell respiration?

extensionS

1. Compare the respiration rate among various types of seeds.

2. Compare the respiration rate among seeds/leaves that have germinated in light or dark.

3. Compare the respiration rate among various types of small animals, such as insects or earthworms.