Lab #10: Exercise and CO2
• Cellular respiration is the process that
takes place your cells; it begins in the
cytoplasm and ends in the mitochondria.
• Your cells go through cellular respiration
because they need the energy that is
stored in glucose.
• The energy of one glucose molecule is
converted into 38 ATPs.
• The harder your cells work the more ATP
• So, they will break down more glucose,
use more oxygen and in turn produce
more carbon dioxide.
• An acid-base indicator such as
bromthymol blue can be used to indicate
the presence of carbon dioxide.
• Bromthymol blue changes to yellow or
green when carbon dioxide is present
• Problem: How will exercise affect your
body’s production of carbon dioxide?
• Hypothesis: If I exercise then, ________.
– Bromthymol blue
– Test tube
– Stop watch
1. Put 5 ml of bromthymol blue solution into
the graduated cylinder and pour into a
2. Your partner will time you during this
step. When your partner says “go”,
slowly blow air through a straw into the
bromthymol blue solution. Caution: Do
not inhale through the straw.
3. When the solution changes color, your
partner should say “stop” and then
record how long the color change took.
4. Jog in place for 2 minutes. Have your partner
rinse out the graduated cylinder and add 5mL
of fresh bromthymol blue to the graduated
5. After you have completed 2 minute of jogging
in place, slowly blow air into the bromthymol
blue. Have your partner time the color change
and record your time.
6. Trade roles with your partner. Repeat steps 1
• Time it takes to change solution from blue
Before exercise After exercise
1. Summarize the lab activity. Retell the
procedure in your own words.
2. How did exercise affect the time for the
solution to change color?
3. Did the results support your hypothesis?
4. What process in your body produces
5. How does exercise affect carbon dioxide
6. What is the function of the mitochondria?
7. What is the equation for cellular
8. Why did we use bromthymol blue in this
9. What are the products of cellular
10. How many molecules of ATP, would 3
molecules of glucose produce? Show