Question

questions
1 what would you deduce the cytoplasm is mostly composed of?
2 what happened to the size of the cell membrane and the amount of cytoplasm of the cell in the salt solution?
3 does the cell wall change in salt water? why or why not?
read this! concentrations: onion cells naturally contain about a 6% salt and 94% water concentration. distilled water has a 0% salt and 100% water concentration. the salt solution we used today had a concentration of 6% salt and 94% water.
cells in distilled water
4 the onion cells would be said to be ____________ (isotonic, hypertonic, hypotonic) compared to the distilled water at the start of the observation.
5 did the cells change in the distilled water? why or why not?
cells in salt water
6 the elodea cells would be said to be ____________ (isotonic, hypertonic, hypotonic) compared to the salt water, at the start of the observation.
7 did the cells change in the salt water? why or why not?
other
8 tap water normally has a 1% salt and 99% water concentration. what would you expect to happen if you used this in the lab. explain.
9 if you are hooked up to an iv for replenishing fluids at the hospital, would you want the solution in the iv to be composed of pure water? why or why not? explain what would happen using terms from your notes.

Explanation:

1. Cytoplasm is mainly composed of water, salts, and various organic molecules.
2. In a salt - solution, water moves out of the cell due to osmosis, so the cell membrane may shrink as the amount of cytoplasm decreases.
3. The cell wall may not change in shape in salt water because it is rigid. However, the cell membrane and cytoplasm inside may shrink away from the cell wall (plasmolysis) due to water loss by osmosis.
4. Onion cells have a higher salt concentration than distilled water, so they are hypertonic compared to distilled water.
5. Cells may change in distilled water. Since distilled water is hypotonic to onion cells, water will move into the cells by osmosis, causing them to swell.
6. Elodea cells have a lower salt concentration than the salt - water solution, so they are hypotonic compared to salt water.
7. Cells will change in salt water. Water will move out of the elodea cells by osmosis (because the salt - water is hypertonic), causing the cells to shrink or plasmolyze.
8. Tap water is hypotonic to onion cells. Water would move into the onion cells by osmosis, causing them to swell slightly.
9. You would not want pure water in an IV. Pure water is hypotonic to human cells. Water would move into the cells by osmosis, causing them to swell and potentially burst (lysis).

Answer:

1. Water, salts, organic molecules.
2. May shrink due to water loss from cytoplasm.
3. Cell wall may not change, but cell membrane and cytoplasm may shrink due to osmosis.
4. Hypertonic.
5. Yes, they may swell as water moves in by osmosis.
6. Hypotonic.
7. Yes, they will shrink as water moves out by osmosis.
8. Onion cells would swell as water moves in by osmosis.
9. No, pure water is hypotonic and can cause cells to swell and potentially burst.