Cell Transport Just passing through Cell Transport What

Cell Transport …Just passing through

Cell Transport What needs to be moved? Trash: Cell waste Food/Raw Materials: Sugars Proteins Hormones Ions Air: O 2 and CO 2

Cell Transport Cell Membrane: Gatekeeper How do materials get into the cell? Semi-permeable Phospho-lipid-bi-layer Ex: goretex, teabags In order for materials to enter or leave the cell they must pass through the cell membrane, the membrane is semipermeable meaning it selectively lets some materials through while blocking others

Cell Transport Passive Transport Three types of passive transport: 1. Diffusion: Small non-polar molecules like CO 2 can fit through the tiny spaces between phospholipids in the plasma membrane, sort of like how you can smell a skunk, even if you’re enclosed in a car. Click to watch animations Diffusion Animation #1 Diffusion Animation #2

Cell Transport Passive Transport 2. Facilitated Diffusion: larger molecules need to use a transport protein, sort of like a door, to get in and out of the cell Membrane proteins help particle cross Still down gradient Used for: Facilitated Diffusion Ions Sugars Amino Acids Particles too large to squeeze through Diffusion

Cell Transport Passive Transport Facilitated Diffusion uses proteins embedded in the plasma membrane to help medium and large particles (too big to fit between the phospholipids) cross into or out of the cell. Ex: We bring glucose into our cells (to use during cell respiration to make ATP) via facilitated diffusion Watch animation Facilitated Diffusion

Cell Transport Passive Transport 3. Osmosis: Movement of water Hypertonic Hypotonic Water (blue) moves freely through pores Solute (green) too large to move across [high] [low]

Cell Transport Passive Transport Osmosis: water moves towards the side of the membrane with the higher concentration of solute particles (water is blue and solute green and red in the animation below) Remember: “Salt Sucks”

Cell Transport Active Transport Characteristics: active transport is like a pump, it uses energy to move particles in the opposite direction of diffusion. Uses Energy (ATP) Moves material AGAINST the gradient [High] [Low] Example: We use active transport to pump sodium ions across the membrane of our nerve cells to help send signals to our muscles to tell them to move. Active Transport Animation: How the Sodium Potassium Pump Works

Cell Transport Exocytosis, etc… XXL size material: materials that are too large to fit through a membrane protein get swallowed or engulfed by the plasma membrane, this is called phagocytosis. Phagocytosis: ‘cell eating’ ex: amoebas use this process to eat while white blood cells use it to engulf harmful bacteria Endocytosis: Bringing material into the cell. Exocytosis: removing XXL material from the cell

Cell Transport Review Quiz yourself! Do you know how different sized particles cross the cell membrane? Can you give examples of the different types of cell transport? ¡ Passive ¡ Small ¡ Medium ¡ Large ¡ XXXL vs. Active

Cell Transport Review Helpful Websites: Diffusion and Osmosis Notes Traffic Across Membranes Concept Map Transport In and Out of Cells

Cell Transport Acknowledgements ¡ http: //www. jacktrash. com/images/garbage_can 2. web. jpg ¡ http: //www. oakland-church. net/home/1804/groceries. jpg ¡ http: //wondertime. go. com/resources/images/your-child/article/boybreath-cold_article. jpg ¡ http: //www. people. virginia. edu/~rjh 9 u/cellmemb. html ¡ http: //arditobook. pbwiki. com/Diffusion ¡ http: //biologycorner. com/bio 1/diffusion. html ¡ http: //www. stanford. edu/group/Urchin/GIFS/exocyt. gif