Biology
Unit 2, Structure of Life, Lab Activity 2-3
Cellular respiration is the release of energy from organic compounds by metabolic
chemical oxidation in the mitochondria within each cell. Cellular respiration involves a
series of enzyme-mediated reactions.
The equation below shows the complete oxidation of glucose. Oxygen is required for this
energy-releasing process to occur. A mole is a measure of the number of molecules. The
energy released is captured by organisms as ATP or released as heat.
C6 H12 O6 + 6 O 2  6 CO 2 + 6 H2 O + 686 kilocalories of energy/mole of glucose oxidized
By studying the equation above, you will notice there are three ways cellular respiration
could be measured. You could measure the:
1. Consumption of O2 . (How many moles of O 2 are consumed in cellular respiration?)
2. Production of CO2 . (How many moles of CO 2 , are produced in cellular respiration?)
3. Release of energy during cellular respiration.
In this experiment, the relative volume of 0 2 consumed (option #1) and the production of
CO2 (option #2) by germinating and non-germinating (dry) peas at two different
temperatures will be measured. The rate of plant respiration will then be compared to the
rate of respiration in an animal using either option #1 or #2.
Research Question
What factors control the rate of cellular respiration in plants and animals?
Write your answer to the research question AFTER completing all parts of the lab.
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PROTOCOL
MATERIALS
Computer
Computer interface
Logger Pro software
O2 or CO 2 Gas Sensor
25 - 50 germinating peas
Same number of non-germinating peas
250 mL respiration chamber
ice cubes
1 large beaker
thermometer
two 100 mL beakers
10 live crickets
Procedure
Data collection for this lab is to be completed as a lab table group. Data reporting and
questions are to be completed individually.
Part I Germinating and non-germinating peas, room temperatures
1. Connect the O 2 or CO 2 Gas Sensor to the computer interface.
2. At the top left of the program select File>Open… and click on Biology with Vernier
folder of Logger Pro. Select 11A Cell Res (O 2 ) if using the O 2 sensor, or 11B Cell
Resp (CO 2 ) if using the CO 2 sensor.
3. Obtain 25 - 50 germinating peas and blot them dry between two pieces of paper
towel. Use a thermometer to measure the room temperature. Record the temperature
in Table 1.
4. Weigh/record mass of the peas in Table 2 and then place the germinating peas into
the respiration chamber.
5. Place the O 2 or CO 2 Gas Sensor into the bottle as shown in Figure 1. Calibrate the O2
sensor if readings are not close to 21% O 2 for room oxygen content. Calibrate the
CO2 sensor if readings are much below 325 ppm. (your teacher will show you how).
Gently push the sensor down into the bottle until it stops. The sensor is designed to
seal the bottle without the need for unnecessary force.
Answer Stop question #1 before collecting data
6. Wait two minutes, then begin collecting data by clicking
. Data will be
collected for 10 minutes.
7. When data collection has finished, remove the O2 (CO 2 ) Gas Sensor from the
respiration chamber. Place the peas in a 100 mL beaker filled with ice water .
8. Use the air supply at you station to blow fresh air into the chamber before
doing another data run.
9. Determine the rate of respiration:
a. Click the Linear Fit button to perform a linear regression. A floating box will
appear with the formula for a best fit line.
b. Record the slope of the line, m, as the rate of respiration for germinating peas at
room temperature in Table 2.
c. Close the linear regression floating box.
10. Move your data to a stored run. To do this, choose Store Latest Run from the
Experiment menu.
11. Obtain the same number of non-germinating peas as you used in step 3 above and
place them in the respiration chamber.
Answer Stop question #2 before continuing
12. Repeat Steps 5 – 10 for the non-germinating peas.
Part II Germinating peas, cool temperatures
13. Remove the peas from the ice water and blot them dry between two paper towels.
Answer Stop question #3 before collecting data
Unit2,Lab2-3,Respirat ionStudentLabPacket2015.docx
Portions adapted fro m Advanced Biology with Vernier by permission
Text 2013 2015 Greg Ballog
Page 2 of 7
Figure 1
16. Repeat Steps 5 – 9 to collect data with the germinating peas at a cold temperature.
17. To print a graph showing all three data runs:
a. Label all three curves by choosing Text Annotation from the Insert menu, and
typing “Room Temp Germinated” (or “Room Temp Non-germinated”, or “Cold
Germinated”) in the edit box. Then drag each box to a position near its respective
curve. Adjust the position of the arrow head.
b. Print a copy of the graph showing all three data sets with regression lines for each
lab member (ask your teacher to show you how to display more than one data set if
necessary).
Answer Stop question #4 before continuing
Part III Animal Respiration
18. Repeat steps 1 - 10 and 13 - 17 using 10 crickets instead of peas. Do not immerse the
crickets in cold water, step 7, following data collection (they don't like that). Instead of
placing them in cold water put then in the refrigerator for 5 minutes. You will only have
two runs (room temperature and cold) for the cricket respiration graphs.
19. Rinse the chambers thoroughly and set them to dry when you are done.
Answer Stop question #5 before collecting data
Now that you have read these procedures construct a flow chart on the following page.
Unit2,Lab2-3,Respirat ionStudentLabPacket2015.docx
Portions adapted fro m Advanced Biology with Vernier by permission
Text 2013 2015 Greg Ballog
Page 3 of 7
Flow Chart
Lab 2-3 Respiration
Unit2,Lab2-3,Respirat ionStudentLabPacket2015.docx
Portions adapted fro m Advanced Biology with Vernier by permission
Text 2013 2015 Greg Ballog
Page 4 of 7
Data
Table 1- O2 Sensor
Condition
Temperature (°C)
room
cold water
Table 2 - O2 Sensor
Treatment
Mass in grams
Rate of Respiration
(%/min)
Germinating Peas , room temperature
Non-germinating Peas, room temperature
Germinating Peas, cool temperature
Cricket, room temperature s
Crickets, cool temperature
tape pea respiration graph here
tape cricket respiration graph here
They will overlap like this
when you have them taped in
Unit2,Lab2-3,Respirat ionStudentLabPacket2015.docx
Portions adapted fro m Advanced Biology with Vernier by permission
Text 2013 2015 Greg Ballog
Page 5 of 7
Stop Questions
1) Predict what will happen with the dry peas. Will they be using any oxygen at all?
________ Explain your reasoning (your explanation is what you will get credit for)
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2) Is it important to calibrate the O 2 sensor? _________Would the rate be the same if
the sensor read a lower %? _______ Explain your reasoning (your explanation is what
you will get credit for) ___________________________________________________
3) Predict what will happen with the cold peas. Will the rate be higher or lower?
____________ Explain your reasoning (your explanation is what you will get credit
for) __________________________________________________________________
4) Did the results you collected agree with your predictions? _________ Support your
answer with specific data from the experiment. _______________________________
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5) Predict what will happen with the crickets. Will there rate of respiration be higher or
lower than the germinating peas? _____________ Explain your reasoning (your
explanation is what you will get credit for) ___________________________________
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Analysis Questions
1. The peas are green. They are plants. Do you think they are also producing oxygen?
_________ Explain your reasoning (your explanation is what you will get credit for)
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2. What part of the plant and animal cells is using the oxygen? _____________________
3. Is the oxygen really gone from the chambers? _____ If Yes, where did it go? If No,
where is it? ______________________________________________________________
4. Why do the peas use oxygen? _____________________________________________
5. Why do the crickets use oxygen? __________________________________________
6. In the chambers the oxygen level drops. In our atmosphere it stays pretty constant at
around 21%. What replenishes the oxygen in our atmosphere that all of the plants and
animals use? __________________________________________
Conclusion
.
Design an experiment that would compare the respiratory rate of a 25 gram reptile and a
25 gram mammal at 10°C. Include a graph of your expected results and explain why you
would expect the results you presented. Your graph will have two lines, one for the
reptile and one for the mammal.
Experimental Design
Manipulated Variable _____________________________________
Responding Variable ______________________________________
Constants ___________________, ______________________, ____________________
Experimental setup ________________________________________________________
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Unit2,Lab2-3,Respirat ionStudentLabPacket2015.docx
Portions adapted fro m Advanced Biology with Vernier by permission
Text 2013 2015 Greg Ballog
Page 6 of 7
Predicted Graph of Results for Conclusion
450
Oxygen gas O2 (%)
Carbon Dioxide gas
CO2 (ppm)
400
350
Explanation of graphed results
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Unit2,Lab2-3,Respirat ionStudentLabPacket2015.docx
Portions adapted fro m Advanced Biology with Vernier by permission
Text 2013 2015 Greg Ballog
Page 7 of 7