8/14/2019 Lab -Effects of Temperature of Membrane Perm Ability

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Nikhilesh Pradhanpartner: Sahil Agarwal

Ms.Illingworth

Lab: Effects of temperature of membrane permeability

Observations:

Temperature( 4C) spectrometer reading (after 10mins)70 0.6255 0.38

40 0.0820 0.18

10 0.21-5 0.48

Analysis:

Temperature vs. membrane premeability

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

-20 0 20 40 60 80

temperature ( 4C)

membranepermeability(spectromete

reading)

Conclusion:As seen in the above table, cells placed in an environment with temperatures that are higheror lower than the temperature to which they are accustom tend to burst more. When thetemperature is below freezing, water expands thereby resulting in the tearing apart of theplasma membrane by water between the phospholipids. When the beet was placed in hot

water, the there was an increase in the kinetic energy of the phospholipids that form thebilayer. This additional energy allowed the phospholipids to move apart thereby increasingthe permeability of the membrane. From this experiment, it can be deduced that the plasmamembranes natural temperature is around 40C.

This lab was limited by the fact that the water temperature was measured by conventionalthermometers which had very small gradation increasing the chances of human error. Theprohibition of cell phones also removed the only available method of precise timing. The

8/14/2019 Lab -Effects of Temperature of Membrane Perm Ability

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Nikhilesh Pradhanpartner: Sahil Agarwal

Ms.Illingworth

analogue clock did not allow for precise timing, unless one was to watch the seconds handfor the required time. However, this would prevent the person from attending to othertasks thereby not allowing the completion of the lab within the assigned time frame. Thissituation can be resolved by the use of stop watches already belonging to the school orrequiring groups of three with one person responsible for time-keeping.

Possible errors could have resulted from slightly inaccurate time-keeping, as spare peoplewere not available to constantly watch the clock. Also determining the exact temperature ofthe water was difficult due to small gradation on the thermometer. This may have beenfurther increased as only the bottom of the thermometer was separated by the hotplateonly by the thin bottom of the beaker. The temperature displayed by the thermometer maynot have been the exact same as the water. Another possible error may have been ourchange in the experiment. Due to time constraints, the time given to the red-colour of thebeet to mix with the water was brought down to 10 minutes. However, it is unlikely that thiscaused any major error as the change was brought to all the beet samples.