Name: ______Date: ______Block: ______

Cell Respiration in Germinating Beans

Cellular 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 by the following equation:

C6H12O6 + 6O26 H2O + 6 CO2 + usable energy (ATP)

Most all organisms oxidize glucose for energy. Often, this energy is used to convert ADP and a phosphate into ATP. It is known that beans undergo cellular respiration during germination. Do beans undergo cellular respiration before germination? The results of this experiment will verify that germinating beans do respire. Using your collected data, you will be able to answer the question concerning respiration and non-germinating beans.

Using the CO2 Gas Sensor, you will monitor the carbon dioxide produced by beans during cellular respiration. Both germinating and non-germinating beans will be tested.

OBJECTIVES

In this experiment, you will:

  • Use a CO2 gas sensor to measure concentrations of carbon dioxide.
  • Study cellular respiration.
  • Confirm that germinating beans respire and determine whether non-germinating beans respire.

MATERIALS

Graphical Analysis (optional)250-mL respiration chamber

LabQuest™ Interface25 germinating beans

Vernier CO2 Gas Sensorthermometer

PROCEDURE

1.Turn on theLabQuest™.

2.Plug the CO2 Gas Sensor into Channel 1 of the LabQuest™ Interface.

3.Obtain 20 germinating beans and blot them dry between two pieces of paper towel.

4. Place the germinating beans into the respiration chamber.

5. Place the shaft of the CO2 gas sensor in the opening of the respiration chamber. Do not twist the shaft of the CO2 gas sensor or you may damage it.

6. Wait one minute, then begin measuring the carbon dioxide concentration by clickingthe play button found on the bottom left of the screen. Collect data for 2 minutes.

7. Remove the CO2 gas sensor and the germinating beans from the respiration chamber.

8. Hold the CO2 gas sensor high above your head and wave it gently to fan air across the openings in the probe shaft for approximately 1 minute.While you are resetting the probe to the original ppm reading, determine the rate of respiration and the correlation number for the data collected.

  • Click on the “Analyze”button at the top of the LabQuest™. Select the “curve fit” option.
  • Click the“linear” regression option under the drop box found on the right-hand screen. If prompted, select “CO2” because that is the sensor you’re using. A box will appear with the formula for a best-fit line.
  • Record the slope of the line, m, as the rate of respiration for germinating beans at room temperature in Table 2. Record the correlation value.
  • Close the linear regression box only once everything is recorded.

9. Dump the used beans in the trash. Rinse the inside of the respiration chamber and shake it dry in the sink to the best of your ability.

  1. Repeat steps 1 through 9 with another member of the lab group.It is important that each individual in the lab group practices using the LabQuest™.

DATA

Room Temperature: ______(°C)

Table 2: Rate of Respiration (ppm/sec) in Germinating Seeds and Dry Seeds.
Name of Individual Collecting the Data / Germinating Seeds / Dry Seeds
Rate of Respiration (ppm/sec) / Correlation Value / Rate of Respiration (ppm/sec) / Correlation Value
1. / .0321 / .9923
2. / -.0124 / .8924
3. / .0052 / .9734
4. / .0421 / .9542
Average / ------ / .0167 / ------

Questions

  1. Do you have evidence that cellular respiration occurred in drybeans? Germinating beans? Explain.
  1. What is the effect of germination on the rate of cellular respiration in beans?
  1. What effect would temperature have on the rate of cellular respiration in beans?
  1. Why do germinating beans undergo cellular respiration?
  1. Imagine you are given 15 germinating beans that have been placed in boiling water for 5 minutes. You place these seeds in the respiration chamber. Predict the rate of carbon dioxideproduction (i.e. cellular respiration) for these seeds and explain your reasoning.
  1. Imagine you are asked to measure the rate of respiration for a 25g reptile at 10°C and at 22°C.Predict how the results would compare and explain the science behind your prediction.

Research Extension:

Besides germination and temperature, addressed above, choose a different condition and/or organism to test and compare the respiration rate.

Experimental Question: ______

______

IV: ______DV: ______

Null Hypothesis: ______

______

Note:These hypotheses do not mandate an “if/then/because” format. However, you must state what you believe that outcome could be and provide valid scientific reasoning to support both proposals.

Alternative Hypothesis 1: ______

______

Alternative Hypothesis 2: ______

______

What potential errors can you anticipate? How could you prevent them?Feel free to think about issues that arose from the practice round to help you.

What statistical tests would you use to analyze your data? State the information each statistic provides to you and why each would be helpful in analyzing your data.

Name of statistical test / Information it provides / Why helpful for your analysis?

What type ofgraph(s) would you use to analyze your data? What is your reasoning for each selection? Use your graph choice chart for assistance if needed.

Extension: Due Next Class

You will choose a different condition and/or organism to test and compare the respiration rate.What factor(s) will your group test in your experiment? Identify your experimental question.

Think about the following:

  • Will the measurements you choose to make provide the necessary data to answer your experimental question?
  • Did you include a control in your experiment?
  • What are possible sources of error in the experiment?

Experimental Question: ______

______

Null Hypothesis: ______

______

Alternative Hypothesis 1: (If/Then/Because): ______

______

Alternative Hypothesis 2: (If/Then/Because): ______

______

MATERIAL:Your materials list should include all items used in your experiment.

-Be very specific

-Do NOT number items, use bullets instead

-Size and number of each item listed

-All measurements in METRIC units

PROCEDURES: Your procedures should include all of the items listed below.

-Number each step

-Each action should be written as a different step (Do not write in paragraph form).

-Write your procedures so that they can be reproduced exactly

-Be very specific- include equipment used in that step

-Procedure steps include an exact description of how measurements will be taken

-Do NOT write in 1st person (no you, I, we)

-Include enough repeat trails (one won’t do)

-Include diagrams if necessary

-No vague statements

The data collection will be on:______

Please make sure to bring all the material that you will need that day.It will be the only block of class time given to collect the data.The rest will need to be done before or after school based off teacher availability.