Osmotic Regulation Virtual Laboratory

Name: ____Justine Basilone___

Osmotic Regulation Virtual Laboratory

Biology

Go to the following virtual laboratory: http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS03/LS03.html Answer your questions in this word document, save the file and submit through Edmodo. Your answers should be at least 2 complete sentences if not more!

Part I: Observations & Data:
Read the Introductory information and the Procedure located in the window to the left of the screen and then perform the laboratory. For your convenience, the data table has been inserted below – fill this one in (the website tends to delete data):

|Molecules Name |Red Blood Cell: |Red Blood Cell: |
| |Net Water Movement In / Out |Appearance of Cell |
|Hypotonic Solution | |Blown up and fat |
| |Moves in to red blood cell | |
|Isotonic Solution | |Normal, did not appear different |
| |Moves in and out of red blood cell | |
|Hypertonic Solution | |Shriveled up |
| |Moves out of red blood cell | |
| |Elodea: |Elodea: |
| |Net Water Movement In / Out |Appearance of Cell |
|Hypotonic Solution | |Gets bigger |
| |Moves in to Elodea | |
|Isotonic Solution | |Appears the same. |
| |Moves in and out of Elodea (stays the same) | |
|Hypertonic Solution |Moves out of Elodea |The inside shrinks and gets smaller |
| |Paramecium: |Paramecium: |
| |Net Water Movement In / Out |Appearance of Cell |
|Hypotonic Solution | |Paramecium blows up and gets bigger. |
| |Moves in to Paramecium | |
|Isotonic Solution | |Seems to stay the same. |
| |Moves in and out of Paramecium | |
|Hypertonic Solution | |Shriveled up and makes the cell appear smaller. |
| |Moves out of Paramecium | |

Part II: Questions & Conclusions: 1) Did water move into the cells or out of the cells while they were surrounded by hypotonic solution? Water moved into all of the cells while they were surrounded by hypotonic solution.

2) In which direction did the water move through the cell membrane when the cells were surrounded by the hypertonic solution? The direction that the water appeared to be moving through the cell membrane was both ways, in and out.

3) Compare and contrast what happens to an animal cell, a plant cell, and a Paramecium cell in a hypotonic, and isotonic, and a hypertonic solution. (Does the cell wall make a difference?)

What seemed to surprise me most is that no matter what cell was used each solution had the same effect of the cells, no matter what kind it was. So no, the cell wall does not appear to make a difference.

4) Could Elodea or Paramecium from a freshwater lake be expected to survive if transplanted into the ocean? Explain.

Since they both react the same to different solutions I do believe that it is possible for both cells to be transplanted in the ocean and survive.

5) If you were to grill a steak, would it be better to put salt on it BEFORE or AFTER you cooked it? Explain why, USING THE TERMS OF OSMOSIS from this activity.

While grilling a steak it is better to put salt on it before you grill it so while it is grilling osmosis will occur and it will retain the salt. So instead of it just sitting on top of the steak it will be on the inside. Giving it more flavor of the salt while eating it.

6) Why does salad become soggy and wilted when the dressing has been on it for a while? Explain why, in terms of osmosis.

The reason why salad becomes soggy and wilted when dressing has been on it for a while is because as it is sitting there osmosis takes place and the salad begins to take in the moisture of the salad dressing, leaving it soggy and wilted.

7) An effective way to kill weeds is to pour salt water on the ground around the plants. Explain why the weeds die, using the principles discovered in this virtual lab.

I believe that the weeds would die due to the fact that as the weeds take in what they think is just water only to later dry out by taking in the salt along with it using osmosis.