Cellular Transport Cellular Transport involves the Cell Membrane
Cellular Transport
Cellular Transport involves the Cell Membrane! PASSIVE TRANSPORT – Energy NOT required • DIFFUSION • OSMOSIS – Hypertonic – Hypotonic – Isotonic – Osmoregulation • FACILITATED DIFFUSION ACTIVE TRANSPORT – Energy REQUIRED! • ENDOCYTOSIS – Carrier Mediated – Phagocytosis – Pinocytosis • EXOCYTOSIS
Passive Transport - energy is NOT required! Diffusion = molecules move from an area of high concentration to an area of low concentration.
Diffusion in the real world. . . • Can occur through air or liquids!
Diffusion is the reason many substances move across the cell membrane! Ex: O 2, CO 2, small/nonpolar molecules
More on diffusion • http: //www. youtube. com/watch? v=STLAJH 7_zk. Y
Diffusion will occur IF: -There is a concentration gradient (DIFFERENCE) across the membrane. -Solution or membrane is permeable. (Allows molecules to pass through!) Membrane is permeable to the stars!
REMEMBER. . . The cell membrane is semi-permeable! *Only small, nonpolar molecules can cross the membrane without help! Permeable: It can pass. Impermeable: Cannot pass.
2 nd Type of Passive Transport: Osmosis: The diffusion of water across the cell membrane. How does water know whether to move into or out of a cell?
Amoeba Sisters: Osmosis https: //www. youtube. com/watch? v=Ia. Z 8 Mt F 3 C 6 M&t=302 s
Recap! • Solute concentration and water concentration are always opposites! – High water conc. = low solute conc. – High solute conc. = low water conc. • Water always moves TOWARD the greater SOLUTE concentration!
Hypertonic solution: Higher solute concentration Hypotonic solution: Lower solute concentration Isotonic solutions: Equal solute concentrations
Egg Cell in hypertonic vs. hypotonic solution • http: //www. youtube. com/watch? feature=en dscreen&NR=1&v=SSS 3 Et. KAz. Yc
3 rd Type of Passive Transport: Facilitated Diffusion: Molecules are transported across the cell membrane by a carrier protein. Ex. Glucose is carried into a red blood cell by a carrier protein.
Active Transport -“Pumping” of molecules from low concentration to high conc. (AGAINST their gradient!) -Requires ATP (energy)! Think about it… Do you like to go where you’ll be more crowded?
Ex: Sodium-Potassium Pump exchanges Na+ for K+ across the plasma membrane of an animal https: //www. youtube. com/watch? v=GTHWig 1 v. On. Y cell.
Endocytosis = The cell membrane surrounds and engulfs large particles. 1. Receptor Mediated Endocytosis = involves carrier proteins on membrane 2. Phagocytosis = Cells bring in large, solid particles (“cellular eating”) 3. Pinocytosis = Cells take up liquid. (“cellular drinking”) https: //www. youtube. com/watch? v=Qspm. Zf_y. Wy. U
Exocytosis Process by which the cell gets rid of large molecules. https: //www. youtube. com/watch? v=VOz. V 4 d 0 HKis
REVIEW! https: //www. youtube. com/watch? v=s. BCDx. Pvu 4 F 0
Recap! Active Vs Passive Transport
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