Transporting Molecules

Diffusion http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png

from “where there’s A LOT” to “where there’s NOT” 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 Happens anytime there is a _____________ in concentration in one place compared to another (________________________) DIFFERENCE = Concentration gradient

DIFFUSION across a space Molecules move automatically from an area of _______ concentration to an area of ________ concentration EX: _____________________ _____________________ Higher 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

SELECTIVELY PERMEABLE

EXAMPLE: Oxygen molecules move automatically from lungs into blood 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? (LOW  HIGH) Example : Glucose into mitochondria Image from: http://www.biologyclass.net/mitochondria.jpg

What if cell needs to move molecules really FAST 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

Kidspiration by: Riedell

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 cell More water enters than leaves cell so cell will ___________________ LESS THAN Swell bigger

OSMOSIS ISOTONIC: Concentration outside cell ____________ EQUALS concentration inside cell Water entering = water leaving so cell _____________________ EQUALS STAYS THE SAME SIZE

Animal cells = cytolysis = crenation http://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gif

Plant cells = Plasmolysis http://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gif Plant cells = Plasmolysis No cytolysis/cell wall keeps it from bursting

VACUOLES store WATER TURGOR PRESSURE _______________________ = http://www.biology4kids.com/files/cell_vacuole.html TURGOR PRESSURE _______________________ = Pressure of water molecules pushing against cell wall

SO WHAT?

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 Diffusion Carrier 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 CHANNEL

ION CHANNELS PASSIVE _____________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 + HIGH  LOW 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

Kidspiration by: Riedell

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

ENDOCYTOSIS Takes 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 ENDOCYTOSIS Takes 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

EXOCYTOSIS Substances 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