Download Respiration Lab-aerobicvsanaerobic

Name _________________
Period # _______
Respiration Lab
Date ______________
Biology
In Class Pre-Cellular Respiration Activity
1. Why do we need to breathe (don’t answer: “to live”)?
2. What makes us breathe harder?
3. When we are running around or playing really hard we sometimes need to stop and we feel
“out of breath”. What does this feel like?
4. Why do you think this happens?
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Name _________________
Period # _______
Respiration Lab
Date ______________
Biology
BREATH OF LIFE- UNLOCKING THE SUGAR INSIDE OF YOU TO MAKE ATP
Measuring the Differences in Carbon Dioxide Production With Varying Activities
Background
Each cell of your body, including your muscle cells, gets ATP energy from sugar by combining the
sugar with oxygen (which you breathe in). The result of this chemical reaction is carbon dioxide
and water. Your body uses some of the water and exhales the carbon dioxide. This process is called
cellular respiration. The process takes 3 steps: glycolysis, Krebs Cycle, and Electron Transport
Chain.
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Krebs Cycle and Electron Transport Chain together are referred to as aerobic respirations
because both require O2 to occur and both produce CO2. Aerobic respiration produces 36
ATP.
Glycolysis is referred to as anaerobic respiration because it does not require O2 and does
not produce CO2. Glycolysis produces 2 ATP.
Exercise can affect which steps of cellular respiration take place and therefore vary the amount
of CO2 produced. Short bursts of activity that require a lot of energy in short amounts of time (01.5 minutes) such as maximum weight lifting and sprinting will use glycolysis and no aerobic
respiration because you are unable to obtain enough O2 to supply the muscles. In order to have
enough ATP to meet the high energy demands, lactic acid fermentation will occur to successfully
continue glycolysis during the activity.
However, during sustained, low energy activities like endurance training (jogging) the muscles have
time and need to produce large amounts of ATP through aerobic respiration.
Bromothymol Blue Indicator Reaction to Measure CO2
When carbon dioxide enters water it makes the water more acidic. Bromothymol blue is a chemical
that changes color (blue to green) if exposed to acid. In other words, Bromothymol Blue will
change colors (blue to green) when CO2 is present. Using the Titration Technique described below,
you can compare the amount of carbon dioxide produced by people at different levels of activity.
The Titration Technique:
Procedure: Use a straw to exhale air into a flask containing a solution of bromothymol blue. When
the solution changes colors, practice changing it back again by adding drops of sodium hydroxide.
The more drops of sodium hydroxide needed, the greater the amount of carbon dioxide in the
flask. Practice this procedure until you are comfortable with adding the sodium hydroxide.
(Important, you need to swirl the flask after adding the drops to see if the color changes,
sometimes the change is delayed)
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Name _________________
Period # _______
Respiration Lab
Date ______________
Pre- Lab: Read the lab and answer the following questions.
Biology
1. What is the purpose (main goal) of cellular respiration?
2. Under what conditions does cellular respiration best achieve its goal? Explain.
3. What does the amount of carbon dioxide a person exhales tell you about the rate of aerobic
respiration?
4. Explain how Bromothymol Blue and sodium hydroxide can determine how much CO2 you
produce.
5. What is the control in this study?
6. Which person in the experiment 1 or 2 is likely to use aerobic respiration for his/ her
activity and which is likely to use anaerobic respiration (glycolysis). Justify your answer.
7. Which person do you expect to produce more CO2 person 1 or person 2? Using your
knowledge about cellular respiration and the background information above, explain your
prediction with a rationale for why you think that.
8. Write a hypothesis for this experiment addressing which person is more likely to perform
aerobic respiration and produce more CO2.
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Name _________________
Period # _______
Respiration Lab
Practice Experiment
Date ______________
Biology
1. Pour 25 mL of Bromothymol Blue solution into a 50 mL beaker.
2. Using a straw, gently blow into the solution until the color changes from blue to green.
3. Using the provided sodium hydroxide (NaOH), use the titration method described above to
determine the amount of CO2 is present. Record that number in chart below. That was
practice. Repeat these steps only if you had trouble titrating the first time.
Experiment
1. Select 2 people in group to be test subjects and assign one person as #1 and the other as
#2.
2. Measure the respiration (breathing) rates (RR) of each person by counting how many
breaths they take normally over 15 seconds and multiplying by 4 for one minute. Record in
table.
3. Pour 100 mL of Bromothymol Blue solution into flask 1 and another 100mL of Bromothymol
Blue solution into flask 2.
4. Using a clean straw, person #1 should be fully rested and blow through his straw into flask
#1 and person #2 should do the same into flask #2.
5. Using the NaOH, titrate both solutions to determine the amount of CO2 present.
6. Person #1 will perform the following activity for 10 seconds: sprinting full speed.
7. At the completion of 10 seconds, person #1 will immediately blow into the flask 1
Bromothymol Blue solution with the same straw until the solution turns green.
8. Also immediately following the exercise, you should get the respiration rate of person #1.
Record in table.
9. Titrate the green solution NaOH until it turns blue and record in table.
10. Person #2 will perform the following activity for 5 minutes: steady jogging.
11. At the completion of 5 minutes, person #2 will immediately blow into the flask 2
Bromothymol Blue solution with the same straw until the solution turns green.
12. Again, also get the respiration rate of person #2 immediately after exercise and record.
13. Titrate the green solution NaOH until it turns blue and record in table.
14. Clean up the flasks and beakers, throw out the straws, and return all equipment to your
station dry.
15. Answer the post-lab questions.
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Name _________________
Period # _______
Respiration Lab
Date ______________
Biology
Data
Practice Titration Amount of NaOH: ____________drops NaOH
Person #
Name
Activity Done
& Time
Resting RR
Per Minute
Exercise RR
Per Minute
# Drops NaOH
at rest
# Drops NaOH
after activity
1
2
Lab Questions
1. Who produced the most CO2 as evidenced by #drops of NaOH and explain why you think you
got this result.
2. How did exercise affect the amount of CO2 produced?
3. Was your hypothesis correct or not? If correct, explain your rationale behind making your
hypothesis that was proven true or if incorrect state what you have learned from this
experiment that proves your hypothesis wrong.
4. Although we are measuring CO2, what 2 processes are we really trying to isolate and test?
What conditions are necessary for each process to occur?
5. Which exercise corresponded to each process identified in question #4 and explain how you
knew using the data you obtained.
6. Which person #1 or #2 was breathing heavier after exercise? Why do you think this was
the case? (use p. 230-231 to help you).
7. What is the purpose of cellular respiration? Write the equation after stating the main goal.
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Name _________________
Period # _______
Respiration Lab
Application Questions
Date ______________
Biology
8. Certain types of bacteria thrive in conditions that lack oxygen. What does that fact
indicate about the way they obtain energy? Which person #1 or #2 in the lab functioned in
a similar way to the bacteria?
9. In certain cases, regular exercise causes in increase in the number of mitochondria in
muscle cells. Which type of exercise, steady low intensity or fast high intensity exercise,
would be most likely to yield this result? Explain your answer being sure to include how the
increase in mitochondria might improve the individual’s ability to perform energy- requiring
activities.
10. Would individuals who carry out steady low intensity exercise suffer more or less muscle
discomfort during and after exercise than an individual performing fast high intensity
exercise? Explain your answer.
11. Knowing that the heart is made of muscle, after a heart attack, small amounts of lactic acid
are present in the blood. What does this evidence suggest about the nature of a heart
attack?
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