Transport of Molecules and Homeostasis Cell Structure and Function Station 3 Transport of Molecules and Homeostasis

Essential Question Why should a freshwater fish never be placed in a saltwater aquarium? Most freshwater fish do not have the mechanisms necessary to adjust to the high levels of salt, so the salt would cause their cells to shrivel and die.

Pre-Preview Questions The diffusion of water molecules in and out of cells is called? Cyclosis Osmosis Active transport Homeostasis

Pre-Preview Questions A red blood cell placed in distilled water will swell and burst due to the diffusion of ? Salts from the cell to the water. Water into the red blood cell. Water from the blood cell into it’s environment. Salts from the water into the red blood cell.

Pre-Preview Questions What would happen if you watered a plant with salt water? The cells would shrivel and pull away from the cell wall. The blood cells would lyse (burst) and break the cell wall. The plant would be rehydrated. The plant would grow faster.

Copy the table into your journal and fill in the data.

2. Using the information recorded in the data tables, draw the beakers, potatoes, and arrows showing which way the water would be going. Solution A Solution B Solution C 25 g. sugar 150 g. sugar distilled water 3. Determine which beaker contains a hypertonic solution, which contains a hypotonic solution, and which contains an isotonic solution.

2. Using the information recorded in the data tables, draw arrows on the beakers below to illustrate what happened to the potato cores in each of the different solutions. Solution A Solution B Solution C 25 g. sugar 150 g. sugar distilled water Hypotonic Hypertonic Isotonic 3. Determine which beaker contains a hypertonic solution, which contains a hypotonic solution, and which contains an isotonic solution.

I need to remember……… Osmosis is the movement of water molecules across a semi-permeable membrane. Sometimes the movement of molecules across a semipermeable membrane requires energy. When the number of molecules inside a cell is equal to the number of molecules on the outside of the cell, homeostasis has been reached—the cell is in equilibrium.

True or False If fertilizer, containing a lot of salt ions, is placed on grass, water will move into the grass cells causing them to become turgid. False

True or False Water molecules can diffuse across the cell memebrane. True

True or False If a potato is soaking in a hypotonic solution, it will lose mass. False

True or False Salt ions can passively diffuse across the cell membrane. False