Osmosis and it's effect on cells as seen through gummy bears

For my science inquiry lesson I determined to tackle the subject of Osmosis and have the students see it as a presence rather than an abstract thought as viewed through their texts. We started off by discussing how a lack of water presents issues not just for people but for environments as well. Then I handed out dehydrated fruit in the class and had them tell me what their thoughts were on the fruit as far as how it had attained the current state from how they commonly see it (I used peaches). Once they were intrigued by the process the fruit had undergone, I brought up the subject of the military's use of MRE's and this caused some intrigue in a class of only boys. 

To tie it in to what we were doing that day I told them that our cells in our bodies act much like the fruit in that if there is a lack of water within the cell then the cell will shrink and wither away, but that there is also the opposite effect whereby when there is too much water then the cell becomes too saturated and explodes. At the thought of a cell exploding the students became excited and wanted to jump right in so I got them started on setting up their experiments and wrote all the instructions on the board while I walked around to each section and repeated the instructions as well. The experiment was set up with four gummy worms to each set (we had one single student due to an absence) and each gummy was placed in saline solution, plain water, fruit punch and lemon juice respectively (please note that the order of the gummies and their solutions go counter clockwise in the pictures. The student forgot to label his containers though he knew which was which). They were left alone for 24 hours and then the liquid that was left was drained and the gummies were inspected and measured for changes. Some of the students found that their hypotheses were not proven and two found that they were way off on their hypotheses (they had hypothesized that the gummies would not be affected as they did not feel permeable). Students had to record their findings on a graphic organizer prepared for them and then discuss their findings/queries in class as a whole group.

What the students all found was that there was a significant difference in how the gummies reacted to the saline solution and the other liquids. Alas none of them was able to create the desired effect of having the gummy bear in the saline solution shrink beacause they added more water than they should have to the solution mix. However, they all realized just what the input of salt did to the cell/bear and what excess water did as well, which was the objective of the lesson.

Attached you will find a copy of one of the student's work. Alas only one student was willing to have his work shared with others hence only one student sample has been attached.

Original pic when bears were just placed in liquids

 

 Gummies after a few hours in liquids..note fruit punch bottom right losing its color.

Gummies after 24 hours.

Gummies after being manipulated by student to check measurments.

Myth or Reality: Polar Ice Caps could flood the world

I conducted the experiment with the ice block and water and was more than a little surprised at the results. Firstly, the ice block did not cause the water to flow over the top of the container like I surmised it would, and secondly the block rose from the bottom to the top without melting or breaking apart. If one were to use the information gleaned from this experiment to theorize what would happen if the polar ice caps melted then one would have to assume that the effect would be the same in that the amount of space that is currently taken by the ice caps would be taken by the water produced by the melt. Therefore, there would be no flood effect and as such the world would be safe. However, one has to be careful not to generalize the results of this experiment to the polar ice caps as there may be variables at play in the real world that are not being accounted for in this experiment.

After having completed the inquiry for this week, I wonder if this effect has been tried on a much larger scale and were the results published? It would be interesting to note the results of such an experiment to note if they were the same as realized in my experiment.

Writing the STEM lesson plan

I was a feeling a bit overwhelmed when I first laid eyes on the lesson plan required for this week's application because it was so much more detailed than I normally am used to in my daily job. However, once I started completing it I found that it was no more difficult than a regular plan; it just required me to look a little more deeply into how I formulated my activities so as to create a positive scientific learning opportunity for the students. I found that I was quite comfortable with the differentiation piece due to having to always having to think about that aspect of my lesson due to the population that I serve as a teacher of Special Education students. What was new for me was the introduction of other pieces that asked me to think beyond my own classroom or state even and think about how the lesson I write conforms to what is considered required learning on a national scale.

The introduction of the 5E's was new for me but it made me have to think logically and creatively about how to design the lesson and really provided a guideline for me to use to ensure that I was meeting the needs of my students. I found myself checking back over what I had written once I started completing the section for the 5E's. While that action may have required more time on my part, I think it lends itself to a more cohesive, well thought out plan.

While I may not have the opportunity outside of this class to include the 5E's as a separate segment on the lesson plan that I currently am required to use in my school, it does provide a platform for me to think about those areas that it covers and write my plan based on those concepts.

I welcome this opportunity to add another technology piece to my toolkit. I hope to develop a greater comfort with using this tool and possibly become proficient enough to introduce it as a permanent tool that is used in the classroom, especially with my eighth graders. We all know how quickly children adapt to changing technology and that they more than adults are intrigued by and motivated to participate in activities purely because they are hosted online or are interactive in some way. The way to reach and teach in this generation is to use the trends that are most utilized by those we want to reach so here goes my blazing trail:)
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