The Big O--Osmosis

First to review Thursday's Cell Membrane - the BuBBle Model:  Write in your lab notebooks what your remember from lab. 25 pts.
1. How did you demonstrate the FLUIDITY and the FLEXIBILITY of the membrane?
2. How did you show how a large item could pass through? (more than one way)
3. How did you show the membrane bound organelles inside the cell?
4. How did you show binary fission - when the cell divided?
[This should be a paragraph of at least 6-8 sentences.)
 

THE EGG-SPIRIMENT...
Last Monday's homework was to sit 3-4 chicken eggs in vinegar so that their shells would dissolve, leaving you with a "naked cell"--no shell but held together with a membrane.
When that is done, it is time for Step Two:  OSMOSIS-- a big word in biology.  It means the passage of water through the membrane, but which way will it go?  Will the water in the egg leave the egg and go into the solution, or will the water in the solution  go through the membrane and into the egg?   We will experiment.

This is what you did to make the "naked eggs." --http://www.exploratorium.edu/cooking/eggs/activity-naked.html

And here are the directions for what to do next:  http://www.exploratorium.edu/cooking/eggs/activity-nakedexperiment.html

BUT READ THIS FIRST:  I had you soak 3-4 eggs because sometimes one breaks, but also so that you can try soaking the third egg in something besides water or corn syrup.  That extra egg or two, could you think of another  liquid to try?  It could be something in your kitchen or in your cleaning supply, but make sure you ask your mom first, nothing toxic, please.  Also, use gloves where appropriate and observe safety precautions.  Call me if you have a question. [no corn syrup? substitute pancake syrup or super-concentrated sugar water.]

IN YOUR LAB Books, record your observations and either draw accurately or take photos and paste in and label.  Then in paragraph form, explain what happened.  ("The egg which was in water grew/shrank/turned purple/whatever..."  50 pts.

Lastly, some Brainpop, which you can do next Tuesday or Wednesday, if you wish.  Movie, quiz, worksheet, FYI-- 15 pts. each        [pcshome/ilearnathome]

• Diffusion  http://www.brainpop.com/science/matterandchemistry/diffusion/
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• Passive Transport http://www.brainpop.com/science/cellularlifeandgenetics/passivetransport/
• 
  
• Active Transport  http://www.brainpop.com/science/cellularlifeandgenetics/activetransport/

Did I say lastly? oops.  Short quiz on vocabulary next Thursday, so review the quizlet and be able to draw and label the prokaryotic cell, and the plant and animal cell.

THIS IS HOMEWORK FOR A WHOLE WEEK, AND DUE ON THURSDAY, BUT YOU MUST NOT PUT OFF THE FIRST AND SECOND PARTS -  first, review the bubble lab and answer the questions in your lab books. Second, get the eggs-piriment started since it will take a few days of watching.  You have time to do it over if it gets messed up, but not time to put it off till the last minute.  http://quizlet.com/19171567/7th-grade-cells-multicellular-organisms-holt-flash-cards/


Thanks for a fun class; I really enjoyed it and appreciated that you were involved without getting too crazy.   I hope you feel like I do, how great and amazing is God's wisdom in creating something so small yet so intricate, which is able to to perform so many complex functions and to work together so elegantly... 
Bless the LORD, O my soul, and every cell that is within me! bless His holy name.