How to Measure Aerobic Respiration
Aerobic respiration is a process in which cells use oxygen to facilitate the transfer of stored food into energy. The rate of respiration refers to how rapidly cells perform this process. It can be difficult to measure this rate because of the prevalence of oxygen in the environment. In the science laboratory, the respiration rate of certain plants can be estimated by measuring the amount of oxygen in a sealed jar.
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Things You'll Need
- 2 respirometer tubes with stoppers
- Cotton
- 15 percent KOH solution
- Dropper
- Germinated bean seeds
- Non-germinated bean seeds
- 2 graduated pipettes
- Tank of room temperature water
- Colored dye
Instructions
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1
Push a wad of cotton into the bottom of each test tube. Saturate the cotton with 15 percent KOH (potassium hydroxide) solution. Use the dropper to apply the solution to each cotton wad. Put the same amount of KOH solution in each test tube.
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2
Put another wad of cotton on top of each saturated wad to stop the KOH from touching the bean seeds.
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3
Fill one of the test tubes halfway with germinated bean seeds. Count and record the number of seeds used. Add the same number of non-germinated bean seeds to the other tube.
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4
Put a graduated pipette in the stopper of each tube. Place the tubes in the tank of water. Check the stoppers to make sure the valves are open.
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5
Put one drop of colored dye into each pipette using the dropper.
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6
Record the time and wait 10 minutes. Close the valves on the stoppers. Every 10 minutes, check the level of dye by reading the markings on the pipettes. Record these measurements. Take at least three measurements. These measurements refer to the level of oxygen in the tube. The difference between the final volume of oxygen and the initial volume of oxygen is the respiration rate.
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Tips & Warnings
Make sure the liquid dye goes far enough into the pipette so that it is easy to read.
References
- Photo Credit science 5 image by Andrey Kiselev from Fotolia.com
