Wednesday and Thursday November 29-30

The last two days we have been covering osmosis and diffusion.  The students have been observing demonstrations in lab. 

Diffusion Demonstration: 
*When iodine contacts starch a purple color is seen.
Diffusion is the process of a substance moving from a high concentration to a low concentration.  The cup represented the cell environment while the baggie represented the cell membrane.  StudentsThrough the demonstration, we saw that only iodine was able to diffuse through the baggie.  The starch molecules were too big to diffuse.

Osmosis Demonstraion

Osmosis is the diffusion of water across a cell membrane.  Look at the observations we made to see what happened to the egg (cell).