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Cell Structure and Function - Chapter 5. Membrane Dynamics. Using “X’s” draw a blood cell in a hypertonic environment. Which way is the water going to move? Why? Label ECF and ICF. Which cell is in a hypertonic environment?. Cell Structure and Function - Chapter 5. Membrane Dynamics.
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Cell Structure and Function - Chapter 5 Membrane Dynamics • Using “X’s” draw a blood cell in a hypertonic environment. Which way is the water going to move? Why? Label ECF and ICF
Cell Structure and Function - Chapter 5 Membrane Dynamics Review Key Terms • Osmosis • Diffusion • ICF/ ECF • Hypertonic/ Hypotonic/ Isotonic • Be able to predict what will happen to water!
Diffusion across a membrane:Passive TransportNo energy req’ddown concentration gradient
Passive Transport: Facilitated Diffusion The passive movement of molecules down its concentration gradient via a transport protein is called facilitated diffusion Aquaporins
Facilitated Diffusion: Gated Ion Channels Some transport proteins do not provide channels but appear to actually translocate the solute-binding site and solute across the membrane as the protein changes shape.
Active TransportRequires E (ATP)Against the concentration gradientUPHILL!
Using The Gradient’s Energy HIGH concentration of H+ ions Chemiosmosis The movement of H+ ions down its concentration gradient is harnessed to the synthesis of ATP. What organelle? How can you concentrate the H+ ions? What protein is shown? LOW concentration of H+ ions
Transport with the MembraneE req’d In phagocytosis, the cell engulfs a particle by extending pseudopodia around it and packaging it in a large vacuole. In pinocytosis, “cellular drinking”, a cell creates a vesicle around a droplet of extracellular fluid Receptor-mediated endocytosis is very specific in what substances are being transported. This process is triggered when extracellular substances bind to special receptors, ligands, on the membrane surface, especially near coated pits. This triggers the formation of a vesicle