Investigation 6: Cellular Respiration There will not be a quiz ...

Investigation 6: Cellular Respiration
There will not be a quiz assessment on this lab. Instead, you are to prepare a
detailed lab report and turn it in Tuesday, November 5.
Learning Objectives
• To learn how a respirometer system can be used to measure respiration rates in plant
seeds or small invertebrates, such as insects or earthworms. You will perform one
measurement using germinating Lentil seeds and a control on Thursday.
To design and conduct your own an experiment
To explore the effect of certain factors, including environmental variables, on the rate of cellular
respiration. You will perform another measurement using organisms of your team’s choice and a
control on Friday. You may bring other forms of seeds or small invertebrates (check with me
ahead of time if you choose invertebrates).
Step 1 Design an experiment to investigate one of your own cellular respiration subject using
microrespirometers. When conducting and reporting your experiment, be sure to address the
following:
Step 2 Record your hypothesis, which should include a prediction about the effect of the
factor(s) you chose to investigate on the rate of cellular respiration (If…then...).
Step 3 Conduct your experiment(s) and record data and any answers to your questions in
your laboratory notebook or as per instructed by your teacher.
Step 4
a) Record your data using appropriate methods, such as the example table provided
in Table 1, p. S78 of your lab manual or the example on the back of this page. Tabulate the
variables that you used in the experiment.
b) Then graph the results to show the effect of the factors/variables you investigated on the
rate of cellular respiration.
c) Calculate the rate(s) of cellular respiration for each factor/variable.
Analyzing Results
Use your data table to construct graphs for the Lentil seed respiration and the
respiration experiment of your lab group. Your goal is to determine respiration rate. Be
sure to title your graph, properly label the x and y- axis and use appropriate units.

Answer the following in your report:
When does cellular respiration occur?
Are there any situations when living cells are not respiring? What are they?
Why might some living cells respire more than others?
Are there differences between major groups of organisms in how fast they respire?
Why?
What is the difference, if any, in the rate of cellular respiration between germinating
seeds and nongerminating seeds?
How does the temperature of germinating seeds affect the rate of cellular respiration?
Do plant seeds consume more oxygen at higher temperatures than at lower
temperatures? Explain why or why not.
Do available nutrients affect the rate of respiration in germinating seeds?