Cellular Respiration

Report
By: MaryKate, Jack, Emily, Reilly and JP
Cellular Respiration Formula:
C6H12O6+ 6O2
6CO2 + 6H2O + Heat
Aerobic Respiration has 3 main steps:
glycolysis, citric acid cycle and the electron
transport chain
Anaerobic Respiration is called fermentation.
There are two types of fermentation:
alcoholic and lactic acid.

 The
cellular respiration experiment is testing
to see how respiration rates change with
different situations. By placing peas in a vial
and changing the temperature one can
examine the different rates of respiration.
According to Avogadro’s Law at a constant
temperature a mole of gas has the same
volume as another mole of gas, therefore
one must add potassium hydroxide, which
creates a solid when reacted with carbon
dioxide. The amount of water that enters the
pipet determines how much gas has left the
vial and the respiration rate.
 In
this experiment we correlated the oxygen
consumption of dried and germinated peas
with their respective rate of cellular
respiration.
 The
germinating seeds will have a greater
rate of cell respiration. The temperature of
the seeds will not cause a major effect on
the rate of respiration within the peas.
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Room temperature water bath
Cold water bath
Container of ice
White paper
Water
Germinating peas
Non-germinating peas
Glass beads
Respirometers
Graduated tube
Absorbent cotton balls
Non-absorbent cotton
15% potassium hydroxide solution (KOH)
Dropping pipets
Forceps
Thermometers
Clock with second hand
Calculator
1) Setup respirometers and water baths.
· One bath should be room temperature while the other is 10oC.
· Place a sheet of white paper on the bottom of each bath to assist in
the reading of the respirometers.
· Set up respirometers for each bath. (Place one absorbent cotton ball
into bottom of respirometer and soak in KOH. Place a piece of nonabsorbent cotton on top of the KOH)
2) Prepare peas and glass beads.
· Put 25 mL of water in each respirometer.
· Drop 25 germinating peas into a graduated tube and measure the
volume. Place these seeds in a respirometer and seal.
· Drop 25 non-germinating seeds into a graduated tube. Add enough glass
beads to equal the volume of the first respirometer. Add these to the
second respirometer.
· Add enough glass beads into a graduated tube to equal the volume of
the first respirometer. Place these beads in the third respirometer.
· Repeat the last four steps to use for the second water bath.
3) Placement of respirometers:
· Place one of each type of respirometer into one of each water bath.
· Wait five minutes before proceeding.
Check the volume of the pipet every five minutes.
By placing potassium hydroxide (KOH) in the respirometer
vial we were able to alter the equilibrium of the gas. The
KOH reacts with the CO2 to form a solid enabling us to view
the amount of oxygen consumption.
COLD BATH
Respirometer 1
Respirometer 2
Respirometer 3
Germinating Peas
Dry Peas + Beads
Only Beads
Degrees
Tim
V of
Chang
Corrected
V of
Chang
Corrected
V of
Celsius
e
Pipet
e in V
V
Pipet
e in V
V
Pipet
Change in V
(Mi
n)
10
10
.67
-
-
.67
-
-
.71
-
10
15
.37
.3
.17
.52
.15
.02
.58
.13
10
20
.28
.39
.25
.51
.16
.02
.57
.14
10
25
.21
.46
.32
.52
.16
.01
.57
.14
10
30
.18
.49
.33
.52
.16
.01
.55
.16
ROOM TEMP
Respirometer 1
Respirometer 2
Respirometer 3
BATH
Germinating Peas
Dry Peas + Beads
Only Beads
Degrees
Time
V of
Change
Corrected
V of
Change
Corrected
V of
Celsius
(Min
Pipet
in V
V
Pipet
in V
V
Pipet
Change in V
)
19
10
.73
-
-
.87
-
-
.9
-
19
15
.58
.15
.14
.87
0
.01
.89
.01
19
20
.41
.32
.31
.87
0
.01
.89
.01
19
25
.33
.4
.39
.87
0
.01
.89
.01
19
30
.2
.53
.52
.87
0
.01
.89
.01
Oxygen Consumption (mL)
0.6
0.5
Germinating Peas at
Room Temperature
Dry Peas at Room
Temperature
Germinating Peas at
Cold Temperature
Dry Peas at Cold
Temperature
0.4
0.3
0.2
0.1
0
10
15
20
25
Time (min)
30
Q: State the controls used for each variable and any means used to
correct for the influence of a variable:
1. The variables that had to be controlled were temperature,
amount of peas, and the size of the respirometer. The control
for the temperature ice was added to make it colder, the control
for the peas was the amount of peas placed in the respirometer,
and there was no control for the size of the container itself.
Another factor was the pressure within the container and the
amount of carbon dioxide produced.
Q: Which of the respirometers serves as a negative control?
2. Respirometer 2 served as a negative control. The corrected
change in volume was the lowest of the three and was negative
for the room temperature peas.
Q: In reference to the general gas law, assuming your
control measures worked, a change to which of the
variables led to the observed change in volume?
3. The change in volume in the respirometer was
caused by the change in pressure and carbon dioxide
present in the respirometer. These factors caused the
volume to decrease as space was filled with carbon
dioxide gas and water was removed.
Q:Using your graph and data tables, summarize your
findings, comparing results from respirometers 1 and
2, and results obtained at room temperature vs.
results at the colder temperature. Speculate as to
cause of any differences between the treatments.
5. The differences in the treatments of cold and
warm show the difficulties of respiration in the cold.
The difference between the germinated and the dry
peas has to do with the fact that the non-germinated
are less active and consume less oxygen.
Q: Calculate the rate of oxygen consumption for each
treatment:
6. a) Germinating seeds at room temp = .34 mL/min
b) Germinating seeds at colder temp = .26 mL/min
c)Dry seeds at room temperature = .01 mL/min
d) Dry seeds at a colder temperature= .015 mL/min
 We
proved our hypothesis to be correct
because the germinating peas consumed
more oxygen than the dry peas in both
temperatures. We were wrong about the
temperature because the peas at room
temperature had a higher rate of oxygen
consumption.

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