Wednesday July 8th, 2015
Review
- Refresher on rules and expectations
- Review of Tuesday's experiments
Icebreaker
- Demonstrates how the protein in gelatin and bromelane enzymes in pineapples don't mix.
- Originally scheduled to complete this experiment yesterday, our class had a few jello-setting set-backs that pushed completing the experiment today.
- Two mixes made and set yesterday in the refridge over night; one mix was plain gelatin, the other was plain gelatin with pineapple chunks added to it.
- The plain mix almost set completely, so the students were able to hypothesize what would happen with the pineapple mix overnight.
- Student compared mixtures side by side and reviewed their predictions worksheet completed yesterday.
- We discussed the results. Students learned that the pineapple contains protein eating in enzymes called bromelane gelatin and that gelatin is a completed protein made of collagen. Collagen is derived from animals, specifically from the joint lining. The sample of gelatin with the pineapple will not set completely as the protein eating enzymes will not allow the protein to coagulate.
- Students marked their results down on their prediction worksheets, and even dropped a quarter in each bowl to see what happened; the quarter in the pineapple sample sank to the bottom while the quarter in the plain mix stuck up top.
- Demonstrates how light passes through different materials.
- Originally scheduled to complete this experiment yesterday, our class had a few jello-setting set-backs that pushed completing the experiment today.
- Mix made yesterday and set in the fridge over night.
- Pulled set jello out of fridge and cut into squares.
- Students began a predictions worksheet as well as an experiment worksheet.
- Tested laser on its own and made notations.
- Placed graph paper down with laser initially at 45 degrees and set jello slice down.
- Class documented results on worksheet and discussed the results.
- Did the laser beam do what you expected it to?
- What effect did the shape of the Jell-O have on how the laser beam traveled?
- Which Jell-O shape represented a concave lens, convex lens, and a prism?
- In what applications do you see lenses being used for and why?
- Several additional shapes were cut out, tested, documented, and discussed.
- The jello acts as a lens. We use the jello lens to see how it effects the path of light. Light paths change from one material to another.
- If the materials have the same index of refraction (speed of light in vacuum divided by the speed of light in the medium), light does not change path and the second material seems to disappear.
- A light beam can only be seen when it reflects off of something like chalk dust in a room or pollen in the air. However, Jello has tiny particles in it that reflect the laser beam as it travels which allows us to see what path the beam is taking. Because red light reflects off of red surfaces but is absorbed by other colors this experiment only works if the laser is the same color as the Jello.
- We tested the attraction reaction between starch and water; mixing the proper water to starch ratio creates a liquidy-solid mixture.
- Made notations on our prediction worksheets; what we mixed together, what we thought would happen, what happened, and why we thought it happened.
- Students noted the varied forces of attraction between the starch molecules and the water as they applied pressure. Student were asked when the attractive forces are strongest and weakest, then documented their results on their predictions worksheet.
- Students begin to think about starch and how it applies to our lesson tomorrow.
Experiment Recap
Reviewed what we learned about the protein eating enzyme bromelane, how light reacts through different lenses, and the strong and weak attractions created by pressure in our starch/water mixture.
Looking Ahead to Tomorrow
Testing for Glucose and Starch Experiment - Demonstrates the amount of starch and glucose in foods.
- We saw how starch and water mixed today. Tomorrow we'll see how starch is in many everyday foods!
No comments:
Post a Comment