What is Elodea?

• The Elodea plant has Plasmolysis the parts that would typically be and found in a plant cell. Cytolysis In this exercise we will identify those parts and see what happens when you subject this plant to plasmolysis.

Elodea Cell Elodea Cell Parts

It is not possible to see the cell membrane because it is pushed up against the cell wall. Also, the central vacuole • Name three structures that are cannot be clearly distinguished from the cell cytoplasm. shown in this plant cell that In a living elodea cell you can “roughly” tell where the you would not expect to find in vacuole is by where the moving chloroplasts are not able an animal cell? to go.

1 What is plasmolysis? Elodea Plasmolysis

• If you were to surround this group of plant cells with salt water then the water inside the plant would move from where there is • This is a view of a cell more water (less salt) through the cell wall and membrane to the that has undergone outside where there is less water (more salt). This process of water movement from a high concentration of water to a lesser plasmolysis. It is now concentration of water is called osmosis. When the water possible to see the movement is out from a cell this form of osmosis is specifically called plasmolysis. cytoplasm which has contracted around the chloroplasts and the other cellular structures. Most of the water that has left the cell has been from the vacuole.

Onion Skin Plasmolysis Types of Solutions

Hypertonic solutions contain higher concentrations of solutes than those in surrounding cells resulting in the cell shrinking in size. Hypotonic solutions contain lower concentrations of solutes than those in surrounding cells resulting in the cell swelling. Isotonic solutions contain equal concentrations of solutes than those in surrounding cells and the cell volume remains Note how the cell membrane draws unchanged. The first figure inward pulling the cell contents along below shows the effect of these with it. solutions on blood cells.

2 Cytolysis/Plasmolysis What solutions were used?

Normal Red Blood Cells

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