1. Crossing the Cell Membrane Osmosis Active Transport Passive transport Diffusion Endo/Exo - Cytosis

2. Warm Up Questions: 1.All _______________ are composed of cells. 2.New cells are produced from _________________. 3.What is the main purpose of the cell membrane? 4.What are some examples of manmade membranes? (Try to think of at least two.)

3. Cell Membranes Made up of a lipid bi-layer Selectively Permeable: Not all particles can pass through the membrane without help from special membrane proteins

4. Active Transport The process by which proteins on the cell membrane push particles from one side of the membrane to the other Requires energy (ATP) Occurs when particles are two large to diffuse through a membrane or; Occurs when particles are moving against the forces of diffusion (Particles are moving from an area of low concentration to an area of high concentration)

5. Active Transport H2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2O AB Na +

6. Active Transport

8. Passive Transport Normal Diffusion that requires membrane proteins Channel Proteins Carrier Proteins

9. Endocytosis Endocytosis is the process by which nutrients are engulfed by the cell membrane

10. Exocytosis The process by which a vesicle inside the cell fuses with the cell membrane and expels its contents outside the cell