Fifth Class: Diffusion Lab

In the fifth class of biology, we conducted a lab to find the effects and rules of diffusion in molecules.  As previously explained in the last blog, diffusion is the ability molecules have to move through semi-permeable surfaces.  This lab showed us that molecules can diffuse based on their size and take longer to move through thicker surfaces. In the picture on the left we placed starch in dialysis tubing and let it soak in Iodine.  The starch turned dark blue form the iodine diffusing in.  We than took some of the remaining iodine out and mixed it with benadicts, while heating it, to see that no starch escaped the tubing and the chemicals bonded to form a brown solution. The middle and rightmost pictures show how far through NaOH can soak through a "cell" of that size in 15 minutes. The last picture is simply for your enjoyment, enjoy.

Yeaaa Baby! -Adam