Respiration Experiment

Problem: To what extent does exercise affect cellular respiration rate?

Research: 1) What is the equation for cellular respiration (reactants are on the left side and products are on the right)?

2) To contract, muscle cells need ATP energy. What two reactants must go into cells through our blood to allow ATP to be made in the muscle cells?

3) What products are released from our cells when they go through respiration?

4) What is the name of the organelle that is in charge of this cellular respiration process (hint: in releases energy / it is the powerhouse)?

5) Predict which cells in your body are have the most mitochondria?

6) What gas coming out of us is a direct measure of our respiration rate?




  1. Please complete your hypothesis.
  2. Take three test tubes and fill them 1/2 full of distilled water. Put 6 drops of bromthymol blue solution in each test tube. Bromthymol blue will turn yellow or green when CO2 is bubbled through the water because the water becomes slightly acidic.
  3. Take a straw, drop it to the bottom of the first test tube. When your partner says "go" begin to blow slowly through a straw into the solution. CAUTION: Do not inhale through the straw. The partner should be watching the time in seconds on the class clock.
  4. When the solution changes colors say "stop" and then record the time in seconds.
  5. Jog in place for 1 minute. CAUTION: Please do not do this if you have a medical condition. Please stop if you feel sick, dizzy, or faint.
  6. After jogging in place for 30 seconds, repeat steps 3 and 4 with the second test tube. Record the results in seconds.
  7. Now repeat steps 3 and 4 after jogging in place for 1 minute.

Data Table:

Seconds of Jogging

graph on

trial 1
time (sec)
of blowing
turning green
trial 2
time (sec)
of blowing
turning green
trial 3
time (sec)
of blowing
turning green


graph on Y-axis

0 seconds
30 seconds
60 seconds

Graph (line graph please):

Effects of Exercise on Respiration Rate

time of blowing into solution before color changed

Seconds of jogging in place


1) Was your hypothesis supported by the data? (restate hyp; give 3 data averages; tell whether support was there)

2) What went well in this experiment? (2 things)

3) What did not go so well in this experiment? (2 things) How could you change it next time to improve these 2 things?

4) What are 2 new related problems that you could test if you were to conduct another experiment on the effects of exercise on respiration rate?

5) What did you learn from this experiment? (2 things)