First Lab

Today in class we had our first lab. We have been studying cells so our teacher made this lab to show us how cell membranes only let in certain substances. First we put corn starch in a plastic bag to simulate the cell membrane, and the corn startch was to indicate when the iodine got past the "cell membrane". Then we put the bag in a beaker full of water with a few drops of iodine mixed in. What was supposed to happen was that the iodine would go through the bag, to simulate a substance going throught the cell membrane, and turn the cornstartch purple. This didn't work out in our class because the plastic bag was to strong to let the iodine in. By the end of class we only got the very bottom of the bag to turn light purple. I had fun during the lab and learning about cells. I hope that the next time we do this the cornstartch turns purple.