470 likes | 599 Vues
Transporting Molecules. Diffusion. http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png. Animatioin from: http://www.biologycorner.com/resources/diffusion-animated.gif. Molecules move from “where there’s A LOT” to “where there’s NOT”.
E N D
Diffusion http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
Animatioin from: http://www.biologycorner.com/resources/diffusion-animated.gif Molecules move from “where there’s A LOT” to “where there’s NOT”
DIFFUSION across a space DIFFERENCE Happens anytime there is a _____________ in concentration in one place compared to another (________________________) = Concentration gradient
DIFFUSION across a space Higher • Molecules move automatically from an area of _______ concentration to an area of ________ concentration • EX: _____________________ _____________________ Lower Perfume, Koolaid, popcorn, BBQ, Bad smell in room http://leighhouse.typepad.com/blog/images/kool_aid.jpg http://www.swapmeetdave.com/Humor/Farts.htm
Molecules need to move across membranes in cells Image modiified from: http://www.accessexcellence.org/AB/GG/importProt.html
If there is a difference in concentration on two sides of a membrane…Diffusion can happen ACROSS A MEMBRANE too! …as long as membrane will let molecule through
Image modified from: http://www.medaille.edu/vmacer/120_graphic_05oxygen.gif EXAMPLE: Oxygen molecules move automatically from lungs into blood DIFFUSION moves them from HIGHER (lungs) concentration to LOWER concentration (blood)
What if cell needs to move large or polar molecules? EX: Glucose Amino acids
What if cell needs to move a molecule AGAINST the CONCENTRATION GRADIENT? Example : (LOW HIGH) Glucose into mitochondria Image from: http://www.biologyclass.net/mitochondria.jpg
What if cell needs to move molecules really FAST? (can’t wait for it to diffuse) Example in cells: Movement of Na + & K+ ions sends nerve signals http://www.steve.gb.com/images/science/neuron.png
WAYS MOLECULES MOVE ACROSS MEMBRANES • PASSIVE TRANSPORT Does NOT require energy • ACTIVE TRANSPORT Requires energy
Kinds of Passive Transport __________________________________ ___________________________________ ___________________________________ ___________________________________ • Diffusion • Osmosis • Facilitated Diffusion • Ion Channels
DIFFUSION across a membrane • Moves from: HIGHER concentration LOWER Any kind of molecule that can pass through the membrane can do this. EX: ______________ ______________ OXYGEN CARBON DIOXIDE http://www.lionden.com/cell_animations.htm
OSMOSIS • MOVES WATER MOLECULES • Across a SEMI-PERMEABLE MEMBRANE • Moves from HIGHER LOWER http://www.Isbu.ac.uk/water/molecule.html
What if there is a difference in concentration but solute molecules can’t move across a membrane? WATER will move until concentration reaches equilibrium
Osmosis1 http://www.sidwell.edu/us/science/vlb6/labs/a_osmosis.gif
OSMOSIS Osmosis4 HYPERTONIC: Concentration outside cell is ____________________ inside cell More water leaves cell than enters so cell ____________ GREATER THAN shrinks
OSMOSIS Osmosis3 HYPOTONIC:Concentration outside cell is ________________ inside the cellMore water enters than leaves cell so cellwill ___________________ LESS THAN Swell bigger
OSMOSIS ISOTONIC: Concentration outside cell ____________ concentration inside cell Water entering = water leavingso cell _____________________ EQUALS STAYS THE SAME SIZE
Animal cells = crenation = cytolysis http://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gif
http://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gifhttp://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gif Plant cells = Plasmolysis No cytolysis/cell wall keeps it from bursting
VACUOLES store WATER http://www.biology4kids.com/files/cell_vacuole.html TURGOR PRESSURE _______________________ = Pressure of water molecules pushing against cell wall
SO WHAT? Bath water is HYPOTONIC compared to you Sitting in the bathtub causes your fingers and toes to wrinkle up when water enters your skin cells by osmosis
Kinds of Passive Transport __________________________________ ___________________________________ ___________________________________ ___________________________________ • Diffusion • Osmosis • Facilitated Diffusion • Ion Channels
Facilitated DiffusionCarrier proteins help diffusion go faster
FACILITATED DIFFUSION NO energy required • Passive = ____________________ • Moves from ________________________ • _____________________ bind molecule, change shape, and release it on other side of membrane (Carrier proteins are _______________ proteins) • Molecules that move this way in cells: _______________________ HIGH LOW Carrier Proteins Integral GLUCOSE
Facilitated Diffusion Animation from: http://bio.winona.edu/berg/ANIMTNS/facdifan.gif
Kinds of Passive Transport __________________________________ ___________________________________ ___________________________________ ___________________________________ • Diffusion • Osmosis • Facilitated Diffusion • Ion Channels
ION CHANNELS PASSIVE HIGH LOW • _____________transport (no energy required) • Molecules move from ___________________ • Small passageways for _______ to get through membrane • Each ion has own kind of passageway • Examples in cells: Na+, Cl- , Ca + + , K + IONS
ION CHANNELS Some channels always open Some channels have “gates” that open or close in response to signals • SIGNALS: • stretching of cell membrane • electrical signals • chemicals Animation from: http://www2.uic.edu/~myilma1/ionchannel.gif
Kinds of Active Transport • Sodium-Potassium Pump ________________________________________ ___________________________________ ____________________________________ • Endocytosis • Exocytosis
SODIUM-POTASSIUM PUMP ATP ACTIVE • ___________ transport (requires energy from ______) • Special just for Na+and K +ions • Uses integral ___________________ to move molecules • Examples in nerve cells: Na+is pumped out of cells at same time K +is taken into cells Carrier Proteins
Na+and K + PUMP Animation from: http://www.lionden.com/cell_animations.htm
ENDOCYTOSISTakes substances into cell • _____________transport (requires energy from ATP) • Uses small membrane sacs to carry substances ______________ ACTIVE = VESICLES http://www.sirinet.net/~jgjohnso/cell.html
2 KINDS of ENDOCYTOSISTakes substances into cell If taking in: fluid, molecules = ____________________ large particles or whole cells = __________________ • Examples in cells: • one celled organisms eat this way • white blood cells get rid of bacteria this way PINOCYTOSIS PHAGOCYTOSIS
ENDOCYTOSIS Animation from: http://academic.brooklyn.cuny.edu/biology/bio4fv/page/cell-movement.html http://www.accs.net/users/kriel/chapter%20nine/
PHAGOCYTOSIS White blood cell destroying germs
EXOCYTOSISSubstances released outside of cell • __________ transport (requires energy) • Substances move in____________ • Examples in cells: • Golgi release packaged proteins ACTIVE VESICLES
Exocytosis http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBooktransp.html
GOLGI BODIES USE EXOCYTOSIS Animation from: http://www.franklincollege.edu/bioweb/A&Pfiles/week04.html
Endocytosis & Exocytosis http://grossmont.gcccd.cc.ca.us/cmilgrim/Bio120/Outline/Outline2.gif/TransportMedia/EndoExocytosisMovie.htm