Lab #10: Exercise and CO2 production

Introduction:• 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 they need.

• 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, ________.

• Materials:– Straws– Bromthymol blue– Test tube– Stop watch

Procedure:1. Put 5 ml of bromthymol blue solution into

the graduated cylinder and pour into a test tube.

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 cylinder.

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 through 5.

Data:

Before exercise After exercise

Write your Name:

Write your Partner’s name:

• Time it takes to change solution from blue to yellow.

Conclusion: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

carbon dioxide? 5. How does exercise affect carbon dioxide

production?

6. What is the function of the mitochondria?7. What is the equation for cellular

respiration?8. Why did we use bromthymol blue in this

experiment?9. What are the products of cellular

respiration?10.How many molecules of ATP, would 3

molecules of glucose produce? Show your work!