11/18/09

Pd.1B

Cell race lab

Standard deviation: 10.54

Average: 18.32

Individual data:

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Class data:

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Standard deviation: 0.0086

Average of class data: 0.009

When comparing the three different sized agar samples, it was noted that agar sample that had the smallest volume, 1 cm³, and the smallest surface area, 6 cm², took the least amount of time to diffuse at 8 minutes and 30 seconds. The sample with a surface area of 24 cm² and a volume of 8 cm³ took a surprisingly large time of 29 minutes and 27 seconds. An interesting fact was that the sample that had a surface area of 34 cm² and a volume of 8 cm³ took less time, than the sample that took 29 minutes and 27 seconds, with a time of 17 minutes. Through research and notes taken in class, it was learned that the larger the surface area-to-volume ratio, the faster the rate of diffusion. Cells do not possess the ability to become extremely large for the simple reason that as the surface area-to-volume ratio approaches 1:1, the cell is no longer able to expand to a larger size. Therefore, instead of bursting, or the more common term “exploding”, the cell simply divides into two new cells. Cell size can be modified so that diffusion can support life processes by increasing the surface area of the cell to decrease the amount of time taken to diffuse.

Team 4 won the race because they had the slowest time needed to diffuse at a rate of 0.003 grams per second. However, this data seems extremely unlikely as agar would require a fairly larger time to diffuse, even if it was being measured per second. Therefore, in reality, the real winner was team 10 with a diffusion rate of .0032 grams per second. In a normal cell, diffusion is necessary in order to transport water and other substances in and out of the cell through the cell membrane. This requires the processes of osmosis and diffusion. For example,...