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Unit 3 Sec 7.3 Homeostasis and Transport
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I. Cell Wall A. Structure Composed of cellulose (__________) Cellulose is a polysaccharide composed of smaller units called _______________ (glucose) Glucose protects and supports cell
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II. Cell Membrane Cell Membrane: Controls what enter and leave cell through selective permeability Boundary of every cell
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II. Cell Membrane A. Membrane Lipids Phospholipid bilayer: Polar hydrophilic head Nonpolar hydrophobic tail Steriods: Cholesterol provides strength and stability in movement
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Cell Membrane
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II. Cell Membrane B. Membrane Proteins Integral proteins: embedded in lipid bilayer & extend from interior exterior of CM
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C. Fluid Mosaic ModelFluid Mosaic Model Phospholipid bilayer acts more like a fluid than a solid
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III. Passive Transport Passive Transport: the movement of substances across the cell membrane without the use of energy
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III. Passive Transport How molecules move: 1. random fashion bouncing off other things 2. constantly in motion From high to low concentrated area Continue until equilibrium
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III. Passive Transport Factors Affecting the Movement Temperature: hot= cold= Size of pores and particle size Mass
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Types of Passive Transport Diffusion Osmosis Facilitated Diffusion
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A. DiffusionDiffusion Diffusion: movement of molecules from an area of _______ concentration to an area of ________________ Diffusion __________________________ Cool Science Trick Cool Science Trick Concentration Gradient:
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A. Diffusion Equilibrium: concentration of substances in an area is _______ Results with: Diffusion Across Membranes:
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B. OsmosisOsmosis Osmosis: diffusion of ________ molecules across cell memb. from area of _______ con. to an area of ________ con. Osmosis Moves:
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Who gets it? 1)What is diffusion? 2)What is equilibrium? 3)What is osmosis?
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B. OsmosisOsmosis Direction of Osmosis: Hypotonic: Concentration of solute is lower outside the cell Hypotonic Hypertonic: Concentration of solute is higher outside the cell Hypertonic Isotonic: solutes in and outside the cell are equal Isotonic
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B. Osmosis How Cells Deal w/ Osmosis: Certain unicellular organisms must maintain a low level of water Use_______________ to get rid of extra water Contractile Vacuole:
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B. Osmosis How cells deal w/ Osmosis: Plant root cells: need a __________ environment Turgor Pressure: Cytolysis Hypertonic Environment.: Plasmolysis:
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C. Facilitated Diffusion Facilitated Diffusion: substances require a ____________ for transport b/c it cannot diffuse through membrane Facilitated Diffusion Molecules that use this transport: Too big Not charged monomers
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D. Diffusion through ion channels Ion Channel: pathway for specific ion to pass through cell membrane Ion Channel Stimuli will control gates to channels: __________________
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IV. Active Transport (AT) 1) AT: movement of materials from a area of ______ concentration to a _______ concentration using energy 2) Molecule is ___________ or not compatible with cell
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IV. Active Transport 3) Bulk Transport:Bulk Transport Used to transport macromolecules or a large quantity of substance A) Endocytosis: a cell will engulf external substances into cell
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IV. Active Transport A. Endocytosis (continued) -2 Types 1) Pinocytosis: cell ___________ 2) Phagocytosis: cell __________
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Endocytosis and Exocytosis
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IV. Active TransportActive Transport B) Exocytosis: process to remove materials from cell a) vesicle w/in the cell is sent to cell membrane b) vesicle fuses w/ the cell membrane & releases substance
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IV. Active Transport C. Pumps: Proteins are embedded in the cell membrane Molecules fit into the protein and are moved across from a _________ to _________ concentration
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