Download Bell Work: What occurs during facilitated diffusion? Why is it

activetransport.notebook
September 26, 2013
Wednesday, October 2
Bell Work:
What occurs during facilitated diffusion? Why is it important that facilitated diffusion occur?
Complete day 3 of the Naked Egg Lab
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activetransport.notebook
September 26, 2013
What is the difference between a water pump and a waterfall?
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activetransport.notebook
September 26, 2013
Active Transport­ movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the use of ENERGY.
­used to get needed molecules regardless of the concentration gradient and to maintain homeostasis.
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activetransport.notebook
September 26, 2013
Transport Proteins­ Span the membrane, change shape when they bind to molecules.
Some bind to only one type of molecule, others to more than one type of molecule.
Key Feature­ All use chemical energy to move a substance against the gradient. Most use ATP.
Example: Neurons need to have a higher concentration of potassium ions and a lower concentration of sodium ions outside the cell. The cell will pump three sodium ions out of the cell for every two potassium ions taken in.
Sodium­Potassium Pump
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activetransport.notebook
September 26, 2013
Endocytosis­ process of taking liquids or fairly large molecules into a cell by engulfing them in a membrane.
Cell membrane makes a pocket around the substance, pocket breaks off inside the cell and forms a vesicle, vesicle fuses with a lysosome to break down the vesicle membrane and release its contents.
Phagocytosis­ cell membrane engulfs large particles
­important part of your immune system
­Macrophages (WBC) engulf bacteria, viruses or other foreign material in your body.
­Pinocytosis­ cells gulp (engulf) droplets of extracellular fluids.
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activetransport.notebook
September 26, 2013
Exocytosis­ release of substances out of a cell.
­Vesicle forms around the substances to be disposed of, the vesicle fuses with the cell membrane and opens out into the cell. Examples: In order to move your big toe(or any muscle) a vesicle containing the chemicals necessary for neuron synapses to occur must release the chemicals inside the vesicle outside the cell.
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activetransport.notebook
September 26, 2013
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