Bio unit 2 pt 1

• includes the lipid bilayer plus protiens and chlesterol
• keep cell contents in
• regulate movement of materials in and out
• permit communication with other cells
• attach to other cells
• control biochemical reactions- metabolism

The Fluid Mosiac Model - membrane is fluid. components remain the same. various protiens float in the phospholipid bilayer

passive- water, dissolved gas (02, Co2), nonpolar or lipid soluble molecules. Vits A, D, E, steroids, lipids. Diffusion and Facilated diffusion

active- larger particles, phagocytosis

both- membrane being selectively permeable. concentration gradients across cell membrane

• passive transport
• polar molecules/ ions that bond with H20- monosaccharides, K, Na, Cl, Ca2
• Use transport protiens
• Protiens are size/charge slective for their target molecule