Download CO2 Lab Activity

Respiratory System
Lab Activity
Names:___________________________
Period:_______ Date:________________
Effect of Exercise on Carbon Dioxide Production
Pre-lab Questions:
1. Why is more CO2 present in exhaled air than inhaled air?
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2. What is the function of the Bromothymol blue solution?
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3. What compound caused the change in the solution?
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4. Effect of Controlled Breathing on CO2 Level:
Blood Condition
Number of Breaths
In 60 Seconds
Normal
High CO2
5. Conclude on how carbon dioxide levels in the blood have on the
breathing rate.
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6. How do increasing CO2 levels affect blood physiology?
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7. Where does CO2 enter the bloodstream and leave bloodstream?
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Effect of Exercise on Carbon Dioxide Production
1. What do you hypothesize about how exercise should affect the
concentration of blood CO2?
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Data Table:
Blood Condition
Number of drops of NaOH solution to change
Bromothymol blue
Before Exercise
After Exercise
2. How can one tell how concentrated the blood is with CO2 in this lab?
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3. Conclude on how exercise affected CO2 blood concentration.
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4. Why do you exhale rapidly after exercise?
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5. How can controlling breathing rate improve exercise performance?
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Breathing Rate Lab Activity
Introduction: The breathing rate can be determined by the amount of
carbon dioxide in the blood. Muscular activity requires energy. Energy
comes from the process of cell respiration. In this process, food is combined
with oxygen and food and the products are energy (ATP) and carbon dioxide.
The more oxygen used the more carbon dioxide produced. You can increase
the carbon dioxide level in the blood through controlled breathing as well.
The amount of carbon dioxide can be measured by using Bromothymol blue
solution. The solution turns yellow in the presence of a weak acid. Carbon
dioxide forms a weak acid when in water. Sodium hydroxide is an basic
solution. In this investigation, you will observe how the amount of carbon
dioxide in the blood affects your breathing rate by using observation and
chemical reactions.
Purpose: To demonstrate how CO2 in the blood affects the breathing rate,
measure breathing rate and determine the effect of exercise on the
production of CO2.
Materials:
Bromothymol blue droppers
1 Erlenmeyer flask 125ml
.116% sodium hydroxide solution
1 drinking straw
Pre-Lab:
1.
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4.
Find a clock with the second hand or watch that measures seconds.
Decide who will be the observer and who will be the test subject.
Have the test subject sit down and relax.
The observer will time for 15 seconds and count how many breaths
the test subject takes in that time period.
5. Multiply that value by 4 to obtain the number of breaths per minute.
Record in data table.
6. The concentration of CO2 in your blood can be increased by holding
your breath. The test subject should sit down and breathe normally.
After exhaling normally, subject then holds his breath for 30 seconds.
When test subject has a strong urge to breathe, return to normal
breathing. Count the number of breaths he takes in the following 15
seconds.
7. Record the data in the table and calculate for breaths per minute and
record.
Effect of Exercise on Carbon Dioxide Production:
1.
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3.
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6.
Fill a 125ml Erlenmeyer flask with 100 ml of water.
Put 5 drops of Bromothymol blue solution into the water and swirl.
Place a drinking straw into the flask solution.
Have observer ready to time test subject.
Test subject blows into the flask for one minute.
Now, add NaOH solution to the flask one drop at a time. Swirl the
flask in between drops. When the color stays blue, stop adding drops.
7. Record the number of drops in data table that were added to change
the flask color.
8. Rinse out flask and fill again with water and add 5 drops of
Bromthymol blue.
9. Now, subject is to exercise vigorously by running in place/jumping
jacks/dancing etc. for 5 minutes.
10. After 3 minutes, test subject returns to lab table and takes a second
to catch breath if needed.
11. Test subject is blows into your flask for one minute.
12. Add the NaOH solution to the flask, drop by drop until it turns back to
blue.
13. Record the number of drops in the data table.
14. Rinse out flask and throw away used straws.
15. Wash hands thoroughly of any chemical residue.