CELL MEMBRANE NOTES Notebook Pg Textbook: Chapter 3.3, 3.4, 3.5 Pg.s 81-95

I. CELL MEMBRANE A. Purpose Maintains homeostasis! regulates the movement of dissolved molecules in and out of cell Provides structure and supportProvides structure and support

I. CELL MEMBRANE B. Structure Semipermeable Lipid BilayerSemipermeable Lipid Bilayer Hydrophilic Phosphorus Heads – love waterHydrophilic Phosphorus Heads – love water Hydrophobic lipid tails – repel waterHydrophobic lipid tails – repel water E (exterior) face and P (protoplasmic) face

The Fluid Mosaic Model

THE FLUID MOSAIC MODEL Fluid Mosiac Video

B. Structure continued …Write on membrane pictureB. Structure continued …Write on membrane picture ProteinsProteins –Integral – transport large materials in and out –Peripheral - Many jobs including lipid digestion and signaling CarbohydratesCarbohydrates –Glycolipids - –Glycolipids - provide energy and also serve as markers for cellular recognition. –Glycoproteins – involved in immunity to diseases Cholesterol – maintains integrity of membrane, keeps it from turning to mush.Cholesterol – maintains integrity of membrane, keeps it from turning to mush. Cytoskeleton (on P Face) -Cytoskeleton (on P Face) - shape, support, and movement. I. CELL MEMBRANE

Other functions of membrane proteins

II. TERMS TO KNOW SOLUTION - a mixture of two or more substances. SOLUTE – The particles in the solution SOLVENT – Dissolves the solute

CONCENTRATION –Refers to the percentage of solutes in a solution. II. TERMS TO KNOW

Equilibrium In a solution, particles move constantly, collide with one another, and tend to spread out randomly and evenly until they reach equilibrium. II. TERMS TO KNOW

III. PASSIVE TRANSPORT - No Energy is Required! A.DIFFUSION particles in a solution move from high concentration to an area of low concentration until equilibrium is reached Food Coloring Diffusion

B. OSMOSIS - specifically the diffusion of water 70% 100 % If the concentration of water inside was 70% and the concentration of water outside was 95%, what would happen to size of the cell? III. PASSIVE TRANSPORT - No Energy is Required !

Osmosis Further Explained 100% Concentration (High) 0% Concentration (Low) 50% Concentration (Equilibrium ) 50% Concentration (Equilibrium)

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Is this really Osmosis???

III. PASSIVE TRANSPORT No Energy Required C. Facillitated Diffusion –Helps large molecules move through the protein channels in membrane –Depends on random particle movements No energy required

IV. Active Transport A. Protein Pumps –Force large molecules to move in and out through protein pumps gainst a concentration gradient. (opposite direction) –ATP Energy is required Potassium PumpSodium Potassium Pump

IV. Active Transport B. Endocytosis –Cell “eats” material by infolding the cell membrane with vesicles Phagocytosis - cell engulfs large food particles Pinocytosis - cell takes in liquid EndocytosisAmoeba Endocytosis

IV. Active Transport C. Exocytosis –Cell releases large amounts of material ExocytosisParamecium Exocytosis

V. TYPES OF SOLUTION A. HYPERTONIC SOLUTION “Hyper” = more –Concentration of SOLUTES is MORE –Water concentration is LESS –Water flows out of cell –The cell shrivels and may die - Plasmolysis Paramecium in Salt Water Plant Cells in Salt Water

V. TYPES OF SOLUTION HYPOTONIC "HYPO" means less Concentration of solutes is LESS Water concentration is HIGH Water flows in The cell swells with water, becomes “turgid”, and dies - Cytolysis Turgid Elodea cells

C. Isotonic Iso = equal Concentration is the same inside and out No net movement The cell stays the same V. TYPES OF SOLUTION Osmosis Summary

Which fish is in a hypertonic solution? Which fish is in a hypotonic solution?

What would have happened to Nemo (a saltwater fish with 40% solute) if he was caputured by someone who didn’t know about osmosis and put him in a freshwater tank with 0% solute?