Williams Biology
Notes Tab (Week 11)
Name: _____________________
Period: _____
Anaerobic Respiration: Investigating Muscle Fatigue
Terms: Aerobic respiration, anaerobic respiration, lactic acid fermentation
__Aerobic__ respiration uses oxygen. There are three steps:
(1) Glycolysis makes __2__ ATP
(2) Krebs Cycle makes __2__ ATP
(3) Electron Transport Chain makes __34__ ATP
__Anaerobic__ respiration happens without oxygen. This is how cells generate energy when there
is not enough oxygen available. There are two steps:
(1) Glycolysis makes __2__ ATP
(2) Fermentation makes __lactic acid__ in animal muscle cells and alcohol / CO2 in yeast cells
Feel the burn Activity:
Purpose: In this activity students will investigate cellular respiration, and the
factors that affect skeletal muscle fatigue. What are the affects of
anaerobic respiration on your muscles?
Background Information: Just as a car needs gasoline as a source of
energy before it can move, so too your muscle cells require ATP in order to contract. This
energy, can be produced with oxygen (Aerobic respiration) or without oxygen (Anaerobic
respiration). Cells prefer to make energy using oxygen, but sometimes there isn’t a steady
amount of oxygen. To stay alive, cells must resort to anaerobic respiration instead.
In animal cells the anaerobic process is called Lactic Acid Fermentation, and it occurs when
cells run out of oxygen. It is less efficient than aerobic respiration, and it results in a buildup of
lactic acid as a byproduct. During anaerobic respiration, muscles have a reduced ability to
contract, until eventually exhaustion sets in and contraction of the muscle stops. This is muscle
fatigue.
Pre-Lab Questions:
1. What determines whether the cell will go through aerobic or anaerobic respiration through
fermentation?
2. What stage of cellular respiration do all cells go through regardless of whether oxygen is
present?
3. If a muscle cell doesn’t have O2 available, what process will it go through after glycolysis?
Materials:
-One clothes pin
-One timer
Time # of Squeezes
Procedure:
0:30
1. Hold a clothes pin in the thumb and index finger of one hand
and open and close it while the other fingers of the hand are
1:00
held out straight. Squeeze quickly and completely, then
1:30
release and repeat, as fast as you can. Count how many
times you can open the clothes pin to its maximum distance.
2:00
2. Every 30 seconds, record the total number of squeezes you
have gotten so far, then keep going immediately (do not
2:30
rest!).
3. After 2:30, you can stop.
4. Prepare a line graph of the data you collected. The time is our __________ variable and
the # of squeezes is our __________ variable. Make sure to label your X and Y axes
clearly and give your graph a detailed title.
0:00
0:30
1:00
1:30
2:30
3:00