Osmosis Lab:
Step 1: In this lab, we will be looking at the elodea plant, a marine plant. Before we do though, we need to know more about the plant cell and the organelles within it. Watch this video (click here), on the first minute 25 seconds, and fill in the table in the performance task.
Step 2: In this step, we are specifically going to zoom in on the vacuole and how it causes turgor pressure in the cell. Another key point before we move on. Watch this video (click here), only the first 1 minute 45 seconds, and answer the questions below.
A. What is the difference in the appearance of a plant that has turgor pressure and another plant that is flaccid?
B. What organelle determines if a plant has turgor pressure or is flaccid?
C. What is going on inside the cell and the vacuole organelle within when the cell is experiencing turgor pressure?
D. What happens when EACH cell in a plant experiences strong turgor pressure?
E. What is the definition of turgor pressure?
F. What happens within a cell experiences weak turgor pressure?
G. What happens to the entire plant when each cell experiences weak turgor pressure.
H. Basically, when a plant experiences weak turgor pressure, the plant becomes ________ (Hint: Starts with an "f").
Step 1: In this lab, we will be looking at the elodea plant, a marine plant. Before we do though, we need to know more about the plant cell and the organelles within it. Watch this video (click here), on the first minute 25 seconds, and fill in the table in the performance task.
Step 2: In this step, we are specifically going to zoom in on the vacuole and how it causes turgor pressure in the cell. Another key point before we move on. Watch this video (click here), only the first 1 minute 45 seconds, and answer the questions below.
A. What is the difference in the appearance of a plant that has turgor pressure and another plant that is flaccid?
B. What organelle determines if a plant has turgor pressure or is flaccid?
C. What is going on inside the cell and the vacuole organelle within when the cell is experiencing turgor pressure?
D. What happens when EACH cell in a plant experiences strong turgor pressure?
E. What is the definition of turgor pressure?
F. What happens within a cell experiences weak turgor pressure?
G. What happens to the entire plant when each cell experiences weak turgor pressure.
H. Basically, when a plant experiences weak turgor pressure, the plant becomes ________ (Hint: Starts with an "f").
Step 3: In this step, we're going to watch a video reviewing osmosis and solutions. Watch this video (Click Here), only the first 6 minutes, and answer the questions below. See picture above to help you understand the differences in solutions.
A. What is osmosis?
B. What always move from an area of ___________ to ___________ concentration.
C. Cell membranes are _____________ permeable, meaning ___________ molecules can pass freely through it, but ________ molecules are unable to.
D. What determines a higher level of concentration?
E. Why can the water, but not the salt, move through semi-permeable membrane?
F. Water will move where there is ______________ solutes?
G. What happened to the saltwater fish when placed in freshwater?
H. How do the kidneys rely on osmosis?
Step 4: Estuaries and intertidal areas undergo daily changes in salinity. Salinity is a measurement of the amount of dissolved salt in a solution. In normal conditions, plants prefer to be in hypotonic solutions (lower concentration of salt than inside the cell). Animal cells prefer to be isotonic solutions (salt concentration is equal between the environment and the cells.) Many organisms in fresh water ecosystems prefer to be hypertonic (higher salt concentration than inside the cell). Osmosis, is what happens when water molecules move across a cell’s membrane from areas of high water concentration (lower salt concentration) to areas low water concentration (higher salt concentration.) Depending on the kind of cell, this movement of water may be harmful. It can result in cell water loss -plasmolysis. Or even cell bursting/lysis - cytolysis. See picture below to see the difference between plasmolysis and cytolysis.
A. What is osmosis?
B. What always move from an area of ___________ to ___________ concentration.
C. Cell membranes are _____________ permeable, meaning ___________ molecules can pass freely through it, but ________ molecules are unable to.
D. What determines a higher level of concentration?
E. Why can the water, but not the salt, move through semi-permeable membrane?
F. Water will move where there is ______________ solutes?
G. What happened to the saltwater fish when placed in freshwater?
H. How do the kidneys rely on osmosis?
Step 4: Estuaries and intertidal areas undergo daily changes in salinity. Salinity is a measurement of the amount of dissolved salt in a solution. In normal conditions, plants prefer to be in hypotonic solutions (lower concentration of salt than inside the cell). Animal cells prefer to be isotonic solutions (salt concentration is equal between the environment and the cells.) Many organisms in fresh water ecosystems prefer to be hypertonic (higher salt concentration than inside the cell). Osmosis, is what happens when water molecules move across a cell’s membrane from areas of high water concentration (lower salt concentration) to areas low water concentration (higher salt concentration.) Depending on the kind of cell, this movement of water may be harmful. It can result in cell water loss -plasmolysis. Or even cell bursting/lysis - cytolysis. See picture below to see the difference between plasmolysis and cytolysis.
In this step, you're going to look at the cells of a type of marine plant, called the elodea placed in first distilled water and then salt water. Usually we would do this lab in school, but since we're online, we will watch this video (click here) instead. As you watch the video, answer the questions below.
A. What type of environment (hypertonic, hypotonic, or isotonic) are the elodea cells in when immersed in distilled water (water free of salts).
B. Describe the appearance within the elodea cells when immersed in distilled water. In your description, include your observations of the cell wall, chloroplasts, and vacuole.
C. What type of environment (hypertonic, hypotonic, or isotonic) are the elodea cells in when immersed salt water?
D. Describe the appearance within the elodea cells when immersed in salt water. In your description, include your observations of the cell wall, chloroplasts, and vacuole.
E. Was there a turgor pressure loss or a gain in the elodea cell when immersed in salt water? Why did this happen?
A. What type of environment (hypertonic, hypotonic, or isotonic) are the elodea cells in when immersed in distilled water (water free of salts).
B. Describe the appearance within the elodea cells when immersed in distilled water. In your description, include your observations of the cell wall, chloroplasts, and vacuole.
C. What type of environment (hypertonic, hypotonic, or isotonic) are the elodea cells in when immersed salt water?
D. Describe the appearance within the elodea cells when immersed in salt water. In your description, include your observations of the cell wall, chloroplasts, and vacuole.
E. Was there a turgor pressure loss or a gain in the elodea cell when immersed in salt water? Why did this happen?