Welcome

If you would like to read the syllabus for the Life Science or Earth Science, please click on the links to access information such as classroom rules, the grading scale, and topics to be discussed.
One last thing that you might find interesting is a NASA picture of the day. Every picture has a great description of what you are seeing.


Enjoy!

Classroom expectations

I expect you to:

1. Always think safety first. NO HORESEPLAY IN THE LAB AREA!
2. Be in the room and prepared for class when the period begins.
3. Do your own work and work on science in science class.
4. Respect each other, yourself, and science as a worthwhile subject.
5. Follow all school rules including the dress code.
6. Take responsibility for your own actions!

I will not tolerate:
1. Swearing, offensive language, or rudeness
2. Tardiness
3. Cell phones in the classroom
4. Cheating
5. Physical Contact – hitting, kicking, pushing, etc.
6. Unsafe Actions – anything that you intentionally do that puts you or someone else in danger
7. Defiance

Tuesday, September 28, 2010

Lab deomonstration for interactions of human systems

The purpose of this lab demonstration is to show the cell membrane function.
The materials used in this lab are dialysis tubing, cornstarch solution, iodine solution, and a beaker.
The preparation for the lab is... cut a strip of dialysis tubing (about 4 inches long).  It needs to be soaked in water for approximately one minute.  One end of the tubing needs to be tied shut.  The cornstarch solution should be added into the tubing and then tied off, so that the tubing has a fleeting resemblance to a water balloon.
The procedure demonstrates how iodine reacts with starch.  The dialysis tubing/cornstarch solution should be placed into the beaker of iodine solution.  The minimum amount of time to wait for results is 5 minutes.
If the dialysis tubing is sealed on both ends, so that none of the cornstarch solution leaks into the iodine solution, the tube of white starch solution will change to a dark purple color.
During the procedure, iodine passes through the dialysis membrane and reacts with the cornstarch.  This is called diffusion.  The cornstarch is not able to diffuse through dialysis membrane because the size of the cornstarch molecules are relatively big. This demonstrates that the cell membrane is selectively permeable because Iodine molecules can pass through the dialysis membrane, when the starch molecules cannot.
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