Hypertonic – more concentrated outside of cell. Study the diagram below. Which arrow shows the direction the solute molecules would move to achieve homeostasis? *remember osmosis will go in the direction from high conc. to low conc.

Today you will review 1. Passive Transport 2. Osmosis 3. Osmosis within the 3 types of solutions.

Types of Cellular Transport  Passive Transport cell doesn’t use energy 1. Diffusion 2. Facilitated Diffusion 3. Osmosis  Active Transport cell does use energy 1. Protein Pumps (sodium-potassium) 2. Endocytosis 3. Exocytosis high low This is gonna be hard work!! high low Weeee!! !

3 Types of Passive Transport 1. Diffusion – molecules move high to low. 2. Facilitative Diffusion – diffusion with the help of transport proteins. 3. Osmosis – Water moves high to low.

 1.Osmosis: diffusion of water through a selectively permeable membrane.  Water moves from high to low concentrations. Water moves freely through pores. Solute (green) too large to move across. Passive Transport: 1. Osmosis

Effects of Osmosis on Life  Osmosis- diffusion of water through a selectively permeable membrane.  There are 3 types of solutions: Isotonic Hypertonic Hypotonic

Isotonic Solution  Solutions that contain the same concentration of solutes as the cytoplasm are called isotonic (or normal saline) solutions.  There is no net movement of water either into or out of the cell.  Cells maintain their normal shape. WATCH VIDEO OF BLOOD IN AN ISOTONIC SOLUTION

Isotonic Solution Isotonic: The concentration of solutes in the external solution is equal to the concentration of solutes inside the cell. Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium) Osmosis Animations for isotonic, hypertonic, and hypotonic solutionsOsmosis

Hypertonic Solution  A hypertonic solution is a solution that contains more (hyper) solutes than the cytoplasm of the cell.  Has less water than the cell and water moves out of the cell.  The cells shrink. WATCH VIDEO OF NORMAL RBCs SUBJECTED TO A HYPERTONIC SOLUTION

Hypertonic Solution Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water) Result: Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis/crenation)! Osmosis Animations for isotonic, hypertonic, and hypotonic solutionsOsmosis shrinks

Hypotonic Solution  A hypotonic solution contains less solute (thus, more water) than the cytoplasm of the cells.  The water will move into the cells resulting in the swelling and lysis of the cells. WATCH VIDEO OF CRENATED RBCs SUBJECTED TO A HYPOTONIC SOLUTION

Hypotonic Solution Hypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water) Result: Water moves from the solution to inside the cell): Cell Swells and bursts open (cytolysis)! Osmosis Animations for isotonic, hypertonic, and hypotonic solutionsOsmosis

Let’s take a closer look! 4/U04L06/rbc.html

What type of solution are these cells in ? A CB HypertonicIsotonicHypotonic

Summary  What is osmosis?  Is osmosis considered passive or active transport?  What are the 3 types of solutions involved in osmosis? ○ 1. ○ 2. ○ 3.

How well did you do today? What is Osmosis? A. The movement of molecules. B. The movement of molecules from an area of high concentration to low concentration. C. The movement of water from a low concentration to a high concentration. D. The movement of water from a high concentration to a low concentration.