Computer
Cell Respiration
11D
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 sufficient
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. Using the CO2 Gas Sensor and O2 Gas Sensor,
you will monitor the carbon dioxide produced and the oxygen consumed by Crickets during cell
respiration. Both room temperature and cooled crickets will be tested.
OBJECTIVES
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.
 Compare the rates of cell respiration in crickets exposed to lower temperatures Crickets
exposed to room temperature
Figure 1
MATERIALS
computer
Vernier computer interface
Logger Pro
Vernier CO2 Gas Sensor
Vernier O2 Gas Sensor
BioChamber 250
10 crickets
PROCEDURE
Form a hypothesis by writing your prediction about the rate of respiration in cold crickets and
warm crickets. Use an “if” “then” statement.
___________________________________________________________________________
Biology with Vernier
11D - 1
Computer 11D
1.
If your CO2 Gas Sensor has a switch, set it to the Low (0–10,000 ppm) setting. Connect the
CO2 Gas Sensor to Channel 1 and the O2 Gas Sensor to Channel 2 of the Vernier computer
interface.
2. Prepare the computer for data collection by opening the file “11D Cell Respiration (CO2 and
O2)” from the Biology with Vernier folder of Logger Pro.
3. Obtain 10 crickets from the front lab counter
4. Place the crickets into the respiration chamber.
5. Place the O2 Gas Sensor into the BioChamber 250 as shown in Figure 1. Insert the sensor
snugly into the grommet. The O2 Gas Sensor should remain vertical throughout the
experiment. Place the CO2 Gas Sensor into the neck of the respiration chamber as shown in
Figure 1.
6. Wait four minutes for readings to stabilize, then begin collecting data by clicking
Collect data for ten minutes and
7. When data collection has finished click
.
.
9. Determine the rate of respiration:
a. Click anywhere on the CO2 graph to select it. 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 your crickets
c. Close the linear regression floating box.
d. Repeat Steps 9a–c for the O2 graph.
DATA
Table 1
Condition
Temperature (°C)
10 Crickets
Table 2
Crickets
CO2
Rate of respiration
(ppt/min)
O2
Rate of consumption
(ppt/min)
Room temperature
Crickets exposed to cold
Difference in respiration rate
11D - 2
Biology with Vernier
Cell Respiration
QUESTIONS
1. Do you have evidence that cell respiration occurred in the crickets? Explain.
2. What is the effect of colder temperatures on the rate of cell respiration in crickets?
3. What molecule were the crickets breaking down to produce ATP energy and CO2 as a by
product?
Biology with Vernier
11D - 3