Cellular Transport Movement of Materials In and Out of a Cell

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Transcript of Cellular Transport Movement of Materials In and Out of a Cell

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Cellular Transport Movement of Materials In and Out of a Cell Slide 2 Plasma Membrane Maintains homeostasis (stable environment) Membrane is selectively permeable Only certain things can pass in and out Slide 3 Structure of the Plasma Membrane Fluid Mosaic Model Membrane is not rigid Molecules can move back and forth (fluid) Slide 4 Phospholipid Bi-layer 2 layers of Phospholipids Hydrophobic tails and hydrophilic heads Slide 5 Cholesterol molecules: sometimes found embedded in membrane to give it more strength and rigidity. Carbohydrate Chains: help cells identify each other Slide 6 Membrane Proteins Protein Channels Provide pathway for movement of certain materials Anchor Proteins Anchor molecules in membrane so they dont move around Enzyme Proteins Take part in chemical reactions Slide 7 Receptor Proteins Act as binding sites for specific molecules Cellular communication Recognize foreign cells Tell cell to begin or stop activity Slide 8 Slide 9 Slide 10 Movement in a Liquid Medium Cytoplasm has many different things dissolved in it. Solvent = water Solute = stuff dissolved (ex: sugar, salt) Solution = the mixture of solvent and solute Concentration = how much is dissolved Slide 11 All molecules are in constant random motion, so over time they will move from one location to another. Slide 12 Types of Transport Slide 13 Passive Transport Doesnt require energy Diffusion: Movement of materials through the cell membrane. Higher concentration to lower concentration Does not require energy (ATP) Ex: oxygen, carbon dioxide, water Slide 14 Dynamic Equilibrium: a point of balance that is reached when concentrations stop changing (but particles still moving!) Slide 15 Example of Diffusion Higher Concentration Outside Particles Diffuse Into Cell Equilibrium Reached (Diffuse In & Out Equally) Slide 16 Facilitated Diffusion: Protein channels facilitate (help) movement of charged ions and large molecules like glucose to cross cell membrane Energy (ATP) not needed Slide 17 Osmosis: Movement (diffusion) of WATER through the cell membrane From high concentration to low (of water) No energy needed Slide 18 Aquaporins: Water channel proteins Involved in osmosis Allow water to move easily through membrane by diffusion Type of facilitated diffusion Oil (fat) and water dont mix Channel helps water get through fatty membrane!!! Slide 19 Water moves into an area that is more concentrated with solute particles!!!! Equilibrium is reached and concentrations are equal on both sides of membrane Slide 20 Osmosis Water moves to area where water is less concentrated Slide 21 Slide 22 Osmotic Pressure: force caused by net movement of water into or out of cell Slide 23 Isotonic Solution: of the same strength Same concentration as cell Hypertonic Solution: above strength More concentrated than cell Hypotonic Solution: below strength Less concentrated than cell Slide 24 What will Happen? To a cell in a: Isotonic Solution? Hypertonic Solution? Hypotonic Solution? Which way will water move? Will it fill up and burst, shrink, or stay the same? Types of Solutions: http://youtu.be/7-QJ-UUX0iYhttp://youtu.be/7-QJ-UUX0iY Egg Experiment: http://youtu.be/SSS3EtKAzYchttp://youtu.be/SSS3EtKAzYc Slide 25 Slide 26 Plasmolysis: when a plant cell loses water Normal plant cell large vacuole stores water In salt water, or in times of drought water leaves cell to go into surroundings (wilts) Slide 27 Active Transport: Requires energy (ATP) Materials are moved from low to high concentration Slide 28 Protein Pumps: Membrane proteins Move small molecules and ions across membrane Against concentration gradient (low to high) Requires energy (ATP) Slide 29 Endocytosis Folding in the membrane to form a vacuole Take in large molecules, clumps of food or whole cells Requires energy Slide 30 Types of Endocytosis Phagocytosis Cell eating Cell engulf large particles by sending out extensions of cytoplasm Ex: Amoeba sends out pseudopods, White blood cells eat bacteria and damaged cells Slide 31 Pinocytosis Cell drinking Cell takes in liquid Pinching in of cell membrane to create a storage vacuole Slide 32 Exocytosis Cells releasing (excreting) materials Membrane of vacuole fuses with cell membrane Slide 33 Inner Life of the Cell http://youtu.be/yKW4F0Nu-UY