1. Homeostasis & Transport

2. Section 1: Diffusion & Osmosis

3. Homeostasis  Homeostasis: the biological balance between a cell or an organism and its environment  Cells maintain homeostasis by controlling and regulating what gets into and out of the cell.  Homeostasis: the biological balance between a cell or an organism and its environment  Cells maintain homeostasis by controlling and regulating what gets into and out of the cell.

4. Passive Transport  Passive Transport: the movement of any substance across a cell membrane without the use of cell energy  Diffusion  Osmosis  Facilitated Diffusion  Gated Channel  Passive Transport: the movement of any substance across a cell membrane without the use of cell energy  Diffusion  Osmosis  Facilitated Diffusion  Gated Channel

5. Diffusion  Diffusion: the process by which molecules move from an area of greater concentration to an area of lower concentration

6. Diffusion

7. Brownian Motion  Brownian Motion: molecules are in a constant state of random motion

8. Brownian Motion

9. Concentration Gradient  Concentration Gradient: the difference in concentration of a substance across a space

10. Dynamic Equilibrium  Dynamic Equilibrium: a state that exists when the concentration of a substance is the same throughout a space

11. Dynamic Equilibrium

12. Review of Cell Membrane Structure

13. Diffusion Across Membranes  Not all molecules can diffuse through all membranes.  The ability of a molecule to pass through a membrane depends on the size and type of molecule and the molecular structure of the membrane.  Not all molecules can diffuse through all membranes.  The ability of a molecule to pass through a membrane depends on the size and type of molecule and the molecular structure of the membrane. Small nonpolar molecules can diffuse through the cell membrane

14. Osmosis  Osmosis: the diffusion of water molecules through a selectively permeable membrane from an area of high water concentration to an area of lower water concentration

15. Osmosis

16. Three Types of Solutions 90% H 2 O 10% solute 90% H 2 O 10% solute 90% H 2 O 10% solute 90% H 2 O 10% solute 85% H 2 O 15% solute 95% H 2 O 5% solute Isotonic (no net movement of water) HypotonicHypertonic

17. Three Types of Solutions Plant Cells

18. Three Types of Solutions Animal Cells

19. Three Types of Solutions Hypotonic solution (a ) Animal cell (b ) Plant cell H2OH2O Cytolysis H2OH2O Turgid (normal) H2OH2O H2OH2O H2OH2O H2OH2O Normal Isotonic solution Flaccid H2OH2O H2OH2O Shriveled Plasmolysis Hypertonic solution

20. Three Types of Solutions

21. Contractile Vacuoles  Contractile Vacuole: an organelle in microorganisms that excretes water  collect excess water → contract → squeeze out water  Contractile Vacuole: an organelle in microorganisms that excretes water  collect excess water → contract → squeeze out water

22. Study the diagram below. It represents a container that is divided by a semipermeable membrane. A different solution in its initial state is shown on each side of the membrane. 1.Describe which molecule(s) will move through the membrane and which molecule(s) will not. 2.Describe the relative rates at which the molecule(s) will move across the membrane. 3.Describe in which direction the molecule(s) will move. 4.Describe how long the molecule(s) will continue to move.

23. Review of Cell Membrane Structure

25. Facilitated Diffusion  Facilitated Diffusion: a process in which substances move down their concentration gradient across the cell membrane with the assistance of a membrane protein  Examples: glucose, fructose, water & ions  Facilitated Diffusion: a process in which substances move down their concentration gradient across the cell membrane with the assistance of a membrane protein  Examples: glucose, fructose, water & ions

26. Two Types of Membrane Proteins: Channels & Carrier Proteins

27. Facilitated Diffusion

28. Aquaporins = Water Channels

31. Gated Channel  Gated Channel: a protein-lined gated passage making cell membranes permeable to certain large molecules as needed  Example: neuromuscular function  Gated Channel: a protein-lined gated passage making cell membranes permeable to certain large molecules as needed  Example: neuromuscular function

32. Gated Channel Protein key made by nucleus Protein key made by nucleus

33. Review of Passive Transport

35. Section 2: Active Transport

36. Active Transport  Active Transport: the movement of any substance across a cell membrane with the use of energy from ATP  Sodium-Potassium Pump  Endocytosis  Exocytosis  Active Transport: the movement of any substance across a cell membrane with the use of energy from ATP  Sodium-Potassium Pump  Endocytosis  Exocytosis

37. Sodium-Potassium Pump  Sodium- Potassium Pump: an active transport mechanism that moves ions in order to achieve polarization

40. Proton Pump  Proton Pump: an active transport mechanism that consumes ATP (energy) to force Hydrogen ions against the concentration gradient

41. Proton Pump

42. Proton Pump & Cotransport

43. Endocytosis  Endocytosis: the process by which a cell engulfs and surrounds large substances

44. Phagocytosis

45. Pinocytosis

46. Receptor- Mediated Endocytosis

47. Exocytosis  Exocytosis: the process by which wastes are packaged in vesicles and leave the cell

48. Exocytosis

49. Passive vs. Active Transport