Cellular respiration is the process your cells use to release the stored energy in your food so they can use it. This process is aerobic, meaning it requires oxygen to be present. The oxygen is used by the cell and carbon dioxide is produced. The body then gets rid of the carbon dioxide as you exhale.
Understand that the production of carbon dioxide is associated with cellular activity.
- 2 beakers (or clear drinking glasses)
- 2 straws
- Bromothymol blue indicator solution
- Partner (optional)
- Soap, water, and towel
- Place 60 ml of water (1/4 cup) in beaker #1.
- Add 8-10 drops of bromothymol blue indicator, also known as BTB, to beaker #1.
- As BTB is exposed to carbon dioxide (CO2) it changes color from blue to a yellow or green color. After placing the BTB in the water do not allow it to sit very long before proceeding.
- Partner 1: Carefully watch the color of the solution. As your partner begins breathing into the solution begin the timer. When you detect a color change stop the timer.
- Partner 2: Begin breathing gently through a straw into the solution in beaker #1 (blowing bubbles). Do not blow with too much force as it can cause the solution to bubble out of the beaker.
- Record the time in Table 1 as Trial 1.
- Repeat steps 1-3 for Trial 2 using beaker 2.
- Average Trial 1 and Trail 2 times. Record as Average Time.
- Wash and dry both beakers.
- Partner 2 now exercises for 60 seconds. This needs to be activity that causes the heart rate and breathing to increase.
- Repeat steps 1-4, but record your findings as Trial 3 and Trial 4.
- Compare the average times of "Before Exercise" and "After Exercise."
- Was there a significant change? Why or why not?