Name: _________________ Period: ______
Partner__________________
Cellular Respiration Activity
Problem​: How does exercise affect the amount of disposal of waste (CO​2​) from cellular respiration?
Hypothesis​: I predict increased exercise will _____________________my amount of carbon dioxide
production because _______________________________________________________________
Materials:
3 small test tubes
10 ml graduated cylinder
test tube rack
bromothymol blue solution
2 straws
clock or stopwatch
goggles
Procedure​:
1. Record your hypothesis, as to how exercise will affect your body’s production of CO​2
2. Label test tubes A, B, and C. Put 10 ml of water and a few drops of bromothymol blue in each
test tube. ​(Bromothymol blue will turn from blue to yellow or green in the presence of
carbon dioxide)
3. When your partner says ‘go’, ​gently​ blow air through the straw into the bottom of test tube B.
CAUTION:​ Do not inhale through the straw!
4. Your partner will record the time it takes for the color to change.
5. Switch roles and repeat for the second partner.
6. Now jog in place for 1 minute and repeat steps 3 through 5 using test tube C.
CAUTION:​ If you feel dizzy or weak while exercising, stop immediately and sit down.
7. When you are finished with your activity, give your results to your teacher.
Data Collection​:
Time for solution
to change
color(sec)
for ME
Time for solution
to change
color(sec)
for my partner
Class Average
Time
(sec)
Before
exercise
After exercise
Data Analysis​:
1. Why did we have test tube A?___________________________________________________
2. What was the Independent Variable? _____________________________________________
3. What was the Dependent Variable?_______________________________________________
4. What process in your body produces carbon dioxide? _______________________________
5. What happens to the carbon dioxide you produce in your cells? ________________________
6. How does exercise affect this process? ___________________________________________
Conclusion:
1. Address your hypothesis:
How did exercise affect the time for the solution to change color? _____________________
___________________________________________________________________________
Did these results support/reject your hypothesis? ____________________________________
___________________________________________________________________________
2. Error analysis – what could be 2 sources of error in this lab?
________________________________________________________________________________
______________________________________________________________________