Osmosis Bellringer: Sketch a cell in a isotonic, hypertonic, and hypotonic solution showing the solute molecules. Objective: SWBAT predict the movement of water molecules during osmosis

Recall: Solute: Whatever is dissolved in the solution. Solvent: what does the dissolving Example: Sugar water

Recall: Passive Diffusion: Movement of molecules across a membrane, without the use a protein carrier Semi-Permeable: only some molecules can pass through the membrane.

Osmosis: Special Type of Diffusion The diffusion (movement) of water through a membrane from an area of high water concentration (less solutes in the water) to low water concentration (more solutes in the water)

Why does Osmosis occur? Osmosis ensures that there is an equal concentration on both sides of the membrane

There MUST be a semi-permeable membrane present for osmosis to occur Cell Membrane There MUST be a semi-permeable membrane present for osmosis to occur

Osmosis—another look…

Practice: Chat Chums Do the front side of the worksheet You have 5 minutes to work with your chat chum

Solutions 3 types Isotonic: Hypotonic: Hypertonic:

Types of Solutions

Isotonic Solution The concentration of molecules is the same on either side of the membrane No net movement of water in or out of the cell

Isotonic Solution: No net movement of water Isotonic Solution: No net movement of water. The same amount of water is entering the cell as leaving. The shape of the cell does not change. Water moves into cell Water out of cell

What do you think would happen to this red blood cell if it were placed in an isotonic environment?

Hypotonic Solution More water outside cell than inside More molecules inside cell than outside

Hypotonic Solution Water moves from the solution into the cell causing it to swell or break called lysis. Water moves into cell

What do you think would happen to this red blood cell if it were placed in an hypotonic environment?

Hypertonic Solution The water moves out of the cell into the solution, causing the cell to shrink

Hypertonic Solution Water moves from the cell into the solution causing it to shrink. Water moves out of the cell

What do you think would happen to this red blood cell if it were placed in an hypertonic environment (distilled water)?