cellular transport chapter 7.4
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Cellular TransportChapter 7.4
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Cell Transportation
• Materials needed for cellular processes must pass into cells so they can be utilized.
• Waste materials from cellular processes must pass out of cells as they are produced.
The Plasma Membrane
• Regulates the passage of material into and out of the cell.
• Depending on the needs of the cell, substances will move either in or out of the cell.
• Because cells exist in a fluid environment, it is possible for substances to move in and out of the cell.
Homeostasis• The necessity of an organism to
maintain a constant or stable condition.
• Dependent on appropriate movement of materials across the cell membrane.
• All organisms have processes and structures which respond to stimuli in ways that keep conditions in their bodies conducive to life.
Homeostasis
• Maintained by the cell membrane.
• The cell membrane is selectively permeable (semipermeable).
• Materials can enter or exit the cell membrane by passive or active transport.
Homeostasis
• How do our cells maintain homeostasis?
• 1)Passive Transport
• 2)Active Transport
http://nestbio.blogspot.com/2010/11/passive-and-active-transport.html
Concentration Gradients
• Molecules move in expected ways based on their concentration gradient.
• At equilibrium, the concentration gradient is the same on both sides, so their is no movement.
Passive Transport• Movement of any substance
through the cell membrane.
• Controlled by the cell membrane.
• Does not require the use of energy.
• Substances move with the concentration gradient.
• HIGH TO LOW GO WITH THE FLOW
• Process by which molecules spread across a cell membrane to reach an equal concentration (equilibrium).
• Slow process dependent on concentration, temperature, and pressure.
• Movement of small ions, atoms, gases, and molecules.
• HIGH TO LOW GO WITH THE FLOW
Passive Transport:Diffusion
Diffusion
• How Diffusion Works Animation
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html
Passive Transport:Osmosis
• The diffusion of H20 through a selectively permeable membrane.
• Water will move in and out of the cell until it reaches equilibrium.
• Dependent on the concentration gradient.
• HIGH TO LOW GO WITH THE FLOW
Osmosis
• How Osmosis Works Animation http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html
Passive Transport:Facilitated Diffusion
• Substances that are not able to pass directly through the cell are able to enter the cell with the aid of transport proteins.
• Occurs along a concentration gradient.
• Ex) Glucose
Facilitated DiffusionProteins
• Integral
• Peripheral
• Channel
• Carrier
• Marker
• Receptor
• Symports
• Pumpshttp://www.clker.com/clipart-49540.html
Facilitated Diffusion
• How Facilitated Diffusion Works Animation http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html
Solutions
SoluteKool Aid Packet
Solvent Water
SolutionKool Aid Drink
Isotonic Solutions
http://imcurious.wikispaces.com/Midterm+Exam+2010+Review+P2
Hypotonic
http://spmbiology403.blogspot.com/2008/08/types-of-solution-hypotonic.html
Hypertonic
http://spmbiology403.blogspot.com/2008/08/types-of-solution-hypertonic.html
Solutions
http://biologyforlife.wordpress.com/2011/03/25/3-2-the-movement-of-substances-across-the-plasma-menbrane-in-everyday-life/
Active Transport• Cells pump molecules through the cell
membrane and require energy.
• Molecules move across the cell membrane against the concentration gradient (low to high).
• Cells use this process to concentrate molecules within the cell or to remove waste from the cell.
• Ex) Calcium, Sodium, and Potassium ions
Active Transport:Proton Pump
• Causes production of ATP molecules (energy).
• Actively transports proteins through the membranes of mitochondria and chloroplasts.
http://bioap.wikispaces.com/Ch+7+Collaboration+2010
Active Transport:Na+/K+ Pump
• Uses ATP to transport Na and K into and out of the cell.
• Nerve cells use the difference in ion concentrations to send signals throughout your body.
http://163.16.28.248/bio/activelearner/05/ch5c4.html
Active Transport:Endocytosis and Exocytosis• When molecules are too large to
pass through the cell membrane, the use of vesicles is required.
• If the large molecule is passing into the cell it is called endocytosis.
• If the large molecule is passing out of the cell it is called exocytosis.
Endocytosis and Exocytosis
http://thescienceupdate.blogspot.com/2010/09/may-force-be-with-you.html
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