determine whether the cell is permeable or impermeable to iodine and starch?

1. If the baggie was permeable to starch, which way would the starch move, into the bag or out of the bag? ___out____

2. If the baggie was permeable to iodine, which way would the iodine move, into or out of the bag? _into___

3. If the baggie was permeable to iodine, what color would you expect the solution in the baggie to turn? __purple_ What about the solution in the beaker? ___stay same___

4. If the baggie was permeable to starch, what color would you expect the solution in the baggie to turn? __stay same___ What about the solution in the beaker? __purple_____

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1. Based on your observations, which substance moved, the iodine or the starch? The iodine moved into the bag

2. How did you determine this? the starch turned purple

3. The plastic baggie was permeable to which substance? permeable to iodine

4. Is the plastic baggie selectively permeable? yes, it allowed iodine to pass through, but not starch

5. Sketch the cup and baggie in the space below. Use arrows to illustrate how diffusion occurred in this lab.


bag and beaker
6. What would happen if you did an experiment in which the iodine solution was placed in the baggie, and the starch solution was in the beaker?
Be detailed in your description. In this case, the iodine would move out of the bag and turn the solution in the beaker purple

7. Why is it not a good idea to store iodine in a plastic bag? it would leak

Well, I am working on this lab right now, also. . .The dialysis tubing is semi-permeable. When starch and iodine react, it turns a purple- blue color. If the tubing had been fully permeable, the solution outside and and inside the bag would have turned this color because starch and iodine would have both been in the solution and the bag. But it was only the iodine that passed through the membrane of the bag (either into the bag or out of it) with the starch staying in one place. Therefore the purple reaction could occur in only one place in each beaker.
This relates to cells because cell membranes are similarly semi-permeable. The rest of that question I am still working on myself, my apologies. . .

I've done this experiment before, however my iodine solution never got out of the visking tubing.
If your iodine solution managed to pass through the partially permeable membrane, then it's probably too big to come to any conclusions, cause both experiments in both beakers will have the same result...

Permeable or semipermeable: Sounds like permeable to me

Relation to cells: Maybe for cell walls alone it would make sence, since the cell walls are fully permeable. And it is possible for cell membranes, seeing as to how iodine solution is able to enter the plant cell and turn blue-black in the presence of starch.

The bag is semi-permeable. It allowed iodine to pass through it, but did not allow sugar (glucose) to enter. It's semi-permeable because not all molecules can pass. If it were permeable, it wouldn't discriminate between molecules. If the bag were a cell, molecules being able to pass depends on polarity and size. Macromolecules and charged particles need help to pass through membranes.

Thank you all ur answer were really helpful... appreciated