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Cell transport. General Biology Name:_____KEY ________________. Introduction to Cell Transport. What is “Cell Transport”? Name of the life process in which materials are exchanged between an organism and its environment.
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Cell transport General Biology Name:_____KEY________________
Introduction to Cell Transport • What is “Cell Transport”? • Name of the life process in which materials are exchangedbetween an organism and its environment
What types of materials need to be transported into/out of living cells? • Water • Glucose • Salt • Ions • Lipids • Amino Acids • Carbon Dioxide • Waste Materials • Ions • Water • Products
All living things are made of one or more cells.In order to maintain homeostasis, each cell must monitor what is able to pass across the boundary which separates the cytoplasm (inside) of the cell from its environment (outside). Environment (solution outside the cell) Cytoplasm (solution inside the cell)
In all organisms (unicellular or multicellular), materials entering or leaving a cell must cross…. The Cell Membrane
Permeability - the ability of a substance to pass through the cell membrane __Impermeable_____: Substance(s) CANNOT pass across the membrane. __Permeable______: Substance(s) CAN easily pass across the membrane. __Selectively Permeable______: The membrane is permeable to some substances and impermeable to others.
Fluid Mosaic Model • Because many different kinds of molecules make up the cell membrane and it changes frequently, the model of the cell membrane is called a fluid mosaic. • Special Proteinmolecules “floating” in the bilayer can help with moving certain materials in/out of cells. • Carbohydrates on the outside of the membrane help cells identify each other
Lipids of cell membrane • Membrane is made of special kind of lipid • phospholipids • Membrane is a double layer • phospholipid bilayer attracted to water Phosphate ‘head’ lipid repelled by water
Video from: http://www.southtexascollege.edu/tdehne/BC_ShockwaveAnimations/08SWF-MembraneStructureAndFunct/08-02-MembraneStructure.swf Only some molecules are able to pass through the membrane easily on their own. Others require some special handling.
VOCAB SOLUTE _____________ = substance that is dissolved in a solvent to make a solution _____________ = substance in which a solute is dissolved __________ = a mixture of a solute evenly dissolved throughout a solvent SOLVENT SOLUTION http://www.makash.ac.il/h_school/hst/hstsb/chem/luach/dissolve.jpg
Images by Riedell CONCENTRATION __________________ = amount of a solute in a given volume of solvent Low concentration High concentration MORE The _______ molecules there are in a given volume the ____________the concentration HIGHER
Practice makes Perfect… • What is the solvent concentration of a solution with a 3% concentration of solute? • 97% • What is the solute concentration of a solution with 75% water? • 25%
There are TWO major types of cell transport: • ACTIVE • PASSIVE
PASSIVE Transport • Does not require ATP • Moves materials from HIGH to LOW concentration • Types: • Simple Diffusion • Facilitated Diffusion (ex. Osmosis)
ACTIVE Transport • DOESrequire ATP • Moves materials from LOW to HIGH concentration, OR moves very large materials in or out of the cell • Types: • Molecular Active Transport • Bulk Transport (Endocytosis / Exocytosis)
Transport summary simplediffusion facilitateddiffusion ATP activetransport
Simple Diffusion http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
Animatiionfrom: http://www.biologycorner.com/resources/diffusion-animated.gif Molecules move _______“where there’s _______” ____“where there’s _______” A LOT FROM to NOT
Simple DIFFUSION across a space DIFFERENCE Happens anytime there is a __________ in concentration in one place compared to another = ________________________ Concentration gradient
Simple DIFFUSION across a SPACE DOWN/WITH from Higher to Molecules move automatically _____ the concentration gradient _______ an area of _______ concentration ____ an area of ________ concentration • EXAMPLES Lower Food coloring in beaker of water demo, Someone making popcorn/grilling out Strong perfume, Bad smell in room http://leighhouse.typepad.com/blog/images/kool_aid.jpg http://www.swapmeetdave.com/Humor/Farts.htm
Simple DIFFUSION across a space equal everywhere Diffusion continues until the concentration is ________________ in space = ________________________ Equilibrium http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
across Diffusion can happen ________ a _____________ in a cell, too membrane …as long as membrane will let the molecule _________________ pass through
Molecules move from high to low • Diffusion • move from HIGH to LOW concentration
CELL EXAMPLE: DIFFUSION automatically moves oxygen from HIGHER concentration (in lungs) to a LOWER concentration (in blood) CO2 automatically movesfrom where there is a HIGHER concentration (in blood) to where there is a lower concentration (in lungs) http://www.le.ac.uk/pa/teach/va/anatomy/case2/2_2.html
Facilitated Diffusion • Movement of materials from an area of HIGH concentration to an area of LOW concentration through a PROTEIN CHANNEL. • No ATP needed (=passive transport)
inside cell inside cell outside cell outside cell Simple vs. facilitated diffusion REMINDER: PASSIVE TRANSPORT = MOLECULES MOVE FROM HIGH TO LOW CONCENTRATION simple diffusion facilitated diffusion lipid H2O protein channel H2O
DIFFUSION across a membrane DIFFERENCE concentration Happens anytime there is a __________ in _____________ on one side of the membrane compared to the other CLICK HERE: “How Diffusion Works http://student.ccbcmd.edu/~gkaiser/biotutorials/eustruct/passiveanim.html
http://bioweb.wku.edu/courses/Biol22000/10Biomembranes/images/membrane.gifhttp://bioweb.wku.edu/courses/Biol22000/10Biomembranes/images/membrane.gif DIFFUSION PASSIVE • No energy required = _______ • Moves _______ concentration gradient from ___________________ • Works for any molecules that can pass through the membrane • Example of molecules that move this way in cells: ________ & ____________ DOWN HIGHER to LOWER OXYGEN Carbon dioxide
Facilitated Diffusion with CARRIER PROTEINS Click here: “How Facilitated Diffusion Works” Animation from: http://bio.winona.edu/berg/ANIMTNS/facdifan.gif Carrier protein grabs molecule, changes shape, and flips across to other side like a revolving door Glucose moves into the cell using carrier proteins! http://www.gobananas.co.uk/edinburgh-stag-party/enquiry/index.htm
FACILITATED DIFFUSION with CHANNELS ________ proteins in the membrane allow _________ molecules to pass through cell membrane by facilitated diffusion. Aquaporin WATER http://www.spps.kvl.dk/news/0507/Lund4.jpg
FACILITATED DIFFUSION with CHANNELS The diffusion of water molecules across a cell membrane is called ______________ OSMOSIS http://student.ccbcmd.edu/~gkaiser/biotutorials/eustruct/channelanim.html
See a video clip about DIFFUSION
Osmosis • Water is very important, so we talk about water separately • Osmosis • diffusion of water from HIGH concentration of water to LOW concentration of water • across a semi-permeable membrane Click me – How Osmosis Works
What if there is a difference in concentration but solute molecules can’t move across a membrane? WATER will move until concentration reaches equilibrium
Animation: http://www.ouhscphysio.org/humanphys/animations/osmosis1.swf Animation http://faculty.etsu.edu/currie/images/osmosis1.jpg
Solute concentration Greater outside than inside Lower outside than inside Equal outside and inside HYPERTONIC HYPOTONIC ISOTONIC What will happen to an animal cell placed in different solutions?
Remember: Cells try to “maintain stable internal conditions = ____________________ HOMEOSTASIS http://bioweb.wku.edu/courses/biol121/Osmosis/Osmosis.asp So an animal cell in ISOTONIC conditions stays same size Water entering = water leaving Video Choose Blood Isotonic link
If cells can’t maintain “stable internal conditions” . . . damage can result and cells can die. http://www.the-aps.org/education/lot/cell/Quiz.htm
Animation from: http://www.ouhscphysio.org/humanphys/animations/osmosis3.swf OSMOSIS HYPOTONIC:Concentration outside cell is ________________ inside the cellMore water enters than leaves cell so cellwill ___________________ Choose Blood Hypotonic link Video LESS THAN swell and possibly burst
Animation from: http://www.ouhscphysio.org/humanphys/animations/osmosis4.swf OSMOSIS HYPERTONIC: Concentration outside cell is ____________________ inside cell More water leaves cell than enters so cell ____________ GREATER THAN shrinks Choose Blood Hypertonic link Video
http://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gifhttp://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gif Animal cells _________ __________ = CYTOLYSIS = CRENATION
http://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gifhttp://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gif Plant cells _____ keeps ___________ plant cells from bursting = PLASMOLYSIS CELL WALL
VACUOLES store WATER http://www.biology4kids.com/files/cell_vacuole.html OSMOTIC PRESSURE _____________________________ = Pressure exerted by the movement of water during osmosis
SO WHAT? Sitting in the bathtub causes your fingers and toes to wrinkle up when water ________ your skin cells by osmosis Bath water is ________________ compared to you hypotonic enters
Grocery stores spray water on their veggies to “plump them up” http://www.painetworks.com/photos/gt/gt0461.JPG