Cell Membrane Functions Provides boundary for cell Selectively
Cell Membrane Functions – Provides boundary for cell – Selectively Permeable: only allows certain things to pass through. “Picky” Ex: Window screen – Maintains homeostasis: balance within the cells
Cell Membrane Structure vs. Function – Membrane is a phospholipid bilayer – Phospholipids: fatty areas that attract (hydrophilic) and repel (hydrophobic) water – Embedded Proteins: “club bouncers” Decide who goes in & ouot Markers for recognition
Movement Across the Membrane Passive Transport: 1. Diffusion 2. Osmosis -Requires No Energy -Movement of like species from area of high concentration to low Active Transport: 1. 2. – – Na+/K+ Pump Endocytosis/Exocytosis Requires Energy Disregard to the concentration gradient
![Passive Transport Diffusion = movement of like species from high [ ] to low](http://slidetodoc.com/presentation_image_h2/7316bfd97653a22ca96dd2f53e66f6b7/image-4.jpg "Passive Transport Diffusion = movement of like species from high [ ] to low")
Passive Transport Diffusion = movement of like species from high [ ] to low [ ].
![Passive Transport Osmosis = movement of water from area of high [solute] to low](http://slidetodoc.com/presentation_image_h2/7316bfd97653a22ca96dd2f53e66f6b7/image-5.jpg "Passive Transport Osmosis = movement of water from area of high [solute] to low")
Passive Transport Osmosis = movement of water from area of high [solute] to low [solute] across selectively permeable membrane Higher Concentration of Water molecules Lower Concentration of Water Sugar molecules
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![• [ ] of dissolved substances is lower outside cell than inside cell](http://slidetodoc.com/presentation_image_h2/7316bfd97653a22ca96dd2f53e66f6b7/image-7.jpg "• [ ] of dissolved substances is lower outside cell than inside cell")
• [ ] of dissolved substances is lower outside cell than inside cell • HYPOTONIC means “below strength” • Water will move INTO cell causing it to SWELL • Cells could rupture if the cell takes in too much water • This increases pressure inside of cell (TURGOR PRESSURE) HYPOTONIC:
![HYPERTONIC: • [ ]of dissolved substances is higher outside the cell, lower inside cell](http://slidetodoc.com/presentation_image_h2/7316bfd97653a22ca96dd2f53e66f6b7/image-8.jpg "HYPERTONIC: • [ ]of dissolved substances is higher outside the cell, lower inside cell")
HYPERTONIC: • [ ]of dissolved substances is higher outside the cell, lower inside cell • HYPERTONIC means “above strength” • H 2 O rushes OUT of cell causing it to shrivel • Can result in PLASMOLYSIS in plants which causes wilting
![[ ] of dissolved substances outside the cell is the same as the inside](http://slidetodoc.com/presentation_image_h2/7316bfd97653a22ca96dd2f53e66f6b7/image-9.jpg "[ ] of dissolved substances outside the cell is the same as the inside")
[ ] of dissolved substances outside the cell is the same as the inside of the cell ISO- means “equal to” Movement into cell = movement out of ISOTONIC:
Passive Transport Facilitated Diffusion = process is used for molecules that cannot diffuse rapidly through the cell membrane.
![Active Transport Movement disregarding the [ ] gradient. Requires energy in the form of](http://slidetodoc.com/presentation_image_h2/7316bfd97653a22ca96dd2f53e66f6b7/image-11.jpg "Active Transport Movement disregarding the [ ] gradient. Requires energy in the form of")
Active Transport Movement disregarding the [ ] gradient. Requires energy in the form of ATP (Adenosine Triphosphate) and protein pumps
Active Transport Endocytosis = the process by which cells ingest external fluid, macromolecules, and large particles. – Pinocytosis = water – Phagocytosis = particles (solids) Exocytosis = the process by which cells remove fluids, macromolecules, and large particles.
Transport Summary
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