Cellular Transport

1. Cellular Transport

2. Cell membrane is selectively permeable Factors that affect permeability: Size Polarity Presence or Absence or Protein Channels or Receptors Cellular Transport

4. Movement of substances from high concentration to low concentration Movement “down a concentration gradient” Due in part to random, rapid motion of molecules. Net Movement Equilibrium State Simple Diffusion. Roles in the Body Factors that Affect Rate: permeability of membrane Size of gradient temperature Diffusion

7. Diffusion of water through a selectively permeable membrane. Movement of water from “less salty” to “more salty” side of membrane from low solute concentration to high solute concentration. from high water concentration to low water concentration. Hypertonic Hypotonic Isotonic In everyday life: Preservation of food Eating of salty or sugary foods Salt on a slug contractile vacuoles turgur pressure in plants Osmosis

8. OSMOSIS DEMONSTRATION(DIALYSIS BAGS)

9. OSMOSIS EXPERIMENTAL RESULTS

10. OSMOSIS IN PLANT CELLS HYPOTONIC SOLUTION= NORMAL TURGOR PRESSURE HYPERTONIC SOLUTION= PLASMOLYSIS

11. OSMOSIS IN PLANT CELLS (Elodea) Plasmolyzed cells

12. Osmosis and Animal Cells NO CHANGE WILL LYSE CRENATION

13. OSMOSIS AND ANIMAL CELLS WILL LYSE CRENATE NO CHANGE

14. Movement from high concentration to low concentration through carrier proteins. Used to move ionic or large substances into or out of cells Passive process Carrier proteins are specific (will only move one substance) Important for moving sugars and amino acids into cells Facilitated Diffusion

16. Movement of substances against a concentration gradient. From low concentration to high concentration. requires energy pumping a substance ATP must be hydrolyzed to fuel this process Sodium-Potassium Pump Pumps sodium out of cells and potassium into cells. Important for the functioning of nerves and muscles. Pump is a membrane protein and an enzyme--ATPase. Active Transport

18. Sodium-Potassium Pump 3 Na+ pumped in for every 2 K+ pumped out; creates a membrane potential

19. Moving the “Big Stuff” Exocytosis- moving things out. Molecules are moved out of the cell by vesicles that fuse with the plasma membrane. This is how many hormones are secreted and how nerve cells communicate with one another.

20. Pinocytosis • Cell forms an invagination • Materials dissolve in water to be brought into cell • Called “Cell Drinking”

21. Example of Pinocytosis mature transport vesicle pinocytic vesicles forming Transport across a capillary cell (blue).

22. Receptor-Mediated Endocytosis Some integral proteins have receptors on their surface to recognize & take in hormones, cholesterol, etc.

23. Endocytosis – Phagocytosis Used to engulf large particles such as food, bacteria, etc. into vesicles Called “Cell Eating”

24. Three Forms of Transport Across the Membrane

25. Cellular Communication Cells communicate with each other via molecular messengers. Communication between adjacent cells occurs in animals via gap junctions, which are like doorways between cells. In plants, plasmodesmataserve as the doorways.

26. Cellular Communication Cells communicate with each other via molecular messengers. Communication between adjacent cells occurs in animals via gap junctions, which are like doorways between cells. In plants, plasmodesmataserve as the doorways.