Wednesday, November 28, 2007

Diffusion 101

For the past few days we have learning the basics of diffusion.
But what is diffusion?

Diffusion refers to the process by which molecules intermingle as a result of their kinetc energy of random motion.

We having been trying to figure out why cells can not get infinetly large. This is because the rate of diffusion will always remain the same; therefore if the cell gets too big the middle out the cell with die because it will not get nutrients fast enough or waste out fast enough. In order words the surface area to violume ratio will work against the cell.

In the cell races lab, six teams compete to make the cell with the most mass and the smallest diffusion time. Congrats to Muskan's group for winning in our class!

In our labs we also tested to see what elements would diffuse across the cell membrane. We set up an experiment with one beakers. In the beaker we placed water and a tester and in the diffusion tube we placed water starch and glucose.

In conclusion we found that the tester, water, and glucose diffused in and out of the cell; however starch did not because the molecule was to big.

Starch looks like this:

or like this:

1 comment:

Dan said...

Very well done Jess. Love the pictures!