7-3 Cell Boundaries Pg. 182

A. Cell Membrane 1. The cell membrane regulates what enters and leaves the cell and also provides protection and support.

A. Cell Membrane 2. Nearly all cell membranes are made up of two layers of lipids called the lipid bilayer.

A. Cell Membrane 3. Scientists describe the function of the cell membrane as the “Fluid Mosaic Model” http://www.classzone.com/cz/books/bio_07/resources/htmls/animated_biology/unit2/bio_ch03_0093_ab_cellmem.html animation

B. Cell Walls 1. Main function is to provide the cell with support and protection. 2. Found in plants, algae, fungi, and many prokaryotes.

Cell Wall Cell Membrane Located in all cells Allows materials to pass through Provides strong support

C. Diffusion through Cell Boundaries 1. Concentration of a solution is the mass of the solute in a given volume of solution. Mass/Volume Example: Which is more concentrate? 4 grams/Liter or 2 grams/Liter

C. Diffusion through Cell Boundaries 2. Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration.

C. Diffusion through Cell Boundaries 3. When the concentration is the SAME throughout a system, the system has reached equilibrium.

C. Diffusion through Cell Boundaries 4. Diffusion depends on random particle movements so the cell doesn’t have to use any energy! http://www.youtube.com/watch?v=H7QsDs8ZRMI P,5 needs video http://www.youtube.com/watch?v=STLAJH7_zkY&feature=fvwrel video

D.Osmosis 1. Diffusion of water through a selectively permeable membrane. P 6 start here

D. Osmosis If you are stranded on a desert island with no water to drink, you are faced with one decision. To drink the sea water or not to drink the sea water? In one sentence, make a choice and explain your decision.

D.Osmosis 2. Types of solutions Isotonic- “same strength” Hypertonic- “above strength” Hypotonic- “below strength” http://www.nclark.net/osmosisPocus.gif http://www.youtube.com/watch?v=SSS3EtKAzYc&feature=fvwrel GIF, video

E. Facilitated Diffusion 1. Movement of specific molecules across cell membranes through protein channels. P5 copied needs explanation

F. Active Transport 1. Process cells use when transporting molecules up a concentration gradient.

F. Active Transport 2. Endocytosis transports larger molecules by infolding, or creating pockets, in the cell membrane. https://www.youtube.com/watch?v=W6rnhiMxtKU p6 exaplain video

F. Active Transport 3. Examples of Endocytosis Phagocytosis- cytoplasm surrounds large particles and takes them in the cell. Pinocytosis- cell takes in liquid from outside environment. https://www.youtube.com/watch?v=W6rnhiMxtKU

F. Active Transport 4. Exocytosis is a process where membrane of vacuole combines with cell membrane to release contents.