CLOTHESPIN LAB
NAME: _____________________________________
Background Information:
Photosynthesis uses carbon dioxide, water and sunlight to make glucose and releases oxygen gas as a waste product.
Glucose is the food for plants and when we eat plants we consume sugars as well. The plant’s ability to make its own
food means that plants are autotrophic. Since animals and other organisms must consume their food they are
heterotrophic.
Aerobic Cell Respiration is the conversion of glucose to ATP in the presence of oxygen gas. The mitochondria of plant
and animal cells will convert the high energy carbohydrate into a form cells can use; this is ATP. When oxygen is not
available, the cell will use Fermentation (an anaerobic pathway) to produce ATP. Animal cells will complete Lactic Acid
Fermentation while plant cells will use Alcoholic Fermentation to continue to produce ATP in oxygen-depleted
environments.
Formulas (use your notes):
Aerobic Cell Respiration: ______________________________________________________________________________
Lactic Acid Fermentation: _____________________________________________________________________________
Vocabulary (use your notes and the reading above):
Aerobic Cell Respiration: ______________________________________________________________________________
Lactic Acid Fermentation: _____________________________________________________________________________
Aerobic: ___________________________________________________________________________________________
Anaerobic: _________________________________________________________________________________________
ATP: ______________________________________________________________________________________________
Question: “What causes your muscles to fatigue?” (Hint-use your notes)
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Complete the following experiment to demonstrate the depletion of available ATP and Oxygen causing the muscle cells
to enter Lactic Acid Fermentation.
Experimental Design:
1. One student pinches a clothespin, also counts pinches
2. Second student watches time and announces time intervals
3. Third student will record the number of pinches on a data table (this information will be copied to all data
tables)
4. Repeat steps 1-3 with each student in the group (each student in the group must use the same method of
pinching the clothespin).
5. Graph your data and answer the following questions using data from notes and lecture.
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CLOTHESPIN LAB
NAME: _____________________________________
Hypothesis: (Example: If I pinch a clothespin continuously for 240 seconds (4 minutes) then I expect _____ will have this
effect on my ability to pinch the clothespin_____________________.)
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Data Table: (Suggestion – Restart your count at each interval and try not to stop too long between intervals)
Student
Name
1.)
30 sec.
60 sec.
90 sec.
120 sec.
150 sec.
180 sec.
210 sec.
2.)
3.)
Line Graph:
Graph the results of each member of the group on the graph. Give your graph a title and label each axis.
(Remember, you are graphing change over time!)
__________________________________________
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240 sec.
CLOTHESPIN LAB
NAME: _____________________________________
Questions: (Answers MUST BE in complete sentence form!)
1.
What is the function of aerobic cell respiration in the body?
___________________________________________________________________________________________
___________________________________________________________________________________________
2. What is the function of lactic acid fermentation in the body?
___________________________________________________________________________________________
___________________________________________________________________________________________
3. At what time interval did each student begin to notice muscle fatigue?
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
4. What was the contributing factor of the muscle fatigue at the cellular level?
___________________________________________________________________________________________
___________________________________________________________________________________________
5. Using the data table, identify the point that you believe lactic acid fermentation starts to occur for each
student._____________________________________________________________________________________
6. Explain why you chose these points:
___________________________________________________________________________________________
___________________________________________________________________________________________
7. During the recovery period, how is oxygen useful to the cell? (use your notes)
___________________________________________________________________________________________
___________________________________________________________________________________________
8. In what two types of cells does lactic acid fermentation occur? (use your notes)
___________________________________________________________________________________________
9. What step is the starting point for both aerobic cellular respiration and fermentation? (use your notes)
___________________________________________________________________________________________
10. Explain why it is beneficial for our cells to be able to extract energy from pyruvic acid when oxygen is not
present.
___________________________________________________________________________________________
___________________________________________________________________________________________
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