crossing the cell membrane
TRANSCRIPT
Crossing the Cell membrane
http://www.biology4kids.com/files/cell_main.html
Diffusion
http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
Molecules move _______“where there’s _______” ____“where there’s ___________”
Animatioin from: http://www.biologycorner.com/resources/diffusion-animated.gif
FROMTO
A LOTNOT A LOT
DIFFUSION across a space
Happens anytime there is a __________ in concentration in one place compared to another. This is called the_____________
DIFFERENCE
Concentration gradient
DIFFUSION across a SPACE• Molecules move automatically
_______ the concentration gradient _______ an area of _______ concentration ____ an area of ________ concentration
• EXAMPLES
HigherLesser
Blue dye in beaker demo, Kool Aid,
http://www.swapmeetdave.com/Humor/Farts.htmhttp://leighhouse.typepad.com/blog/images/kool_aid.jpg
DOWNfrom
to
someone making popcorn, grilling out, strong perfume, bad smell in room
DIFFUSION across a space
Diffusion continues until the concentration is _________in space = ___________
Equilibrium
http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
ballanced
Kidspiration by: Riedell
Kinds of ________ Transport
•Ion Channel
•Osmosis•Facilitated Diffusion
__________________________________
___________________________________
___________________________________
PASSIVE
Molecules need to move across
membranes in cells
Image modiified from: http://www.accessexcellence.org/AB/GG/importProt.html
Diffusion can happen ________ a _____________ in a cell
…as long as membrane will let the molecule _________________
acrossmembrane
pass through
DIFFUSION across a membrane
Happens anytime there is a __________ in _____________ on one side of the membrane compared to the other
difference
Examples of molecules that move by diffusion across membranes in cells:
OXYGEN, WATER, CARBON DIOXIDE, NITROGEN
http://www.lionden.com/cell_animations.htm
See diffusionanimation
concentration
DIFFUSION automatically moves oxygen from HIGHER concentration (in lungs) to a LOWER concentration (in blood)
http://www.le.ac.uk/pa/teach/va/anatomy/case2/2_2.html
CELL EXAMPLE:
CO2 automatically movesfrom where there is aHIGHER concentration (in blood) to where thereis a lower concentration (in lungs)
SELECTIVELY
PERMEABLE(Semi-
permeable)MOVIE DIFFUSION ACROSS THE
MEMBRANE
http://life.nthu.edu.tw/~d857401/advance.html
OSMOSIS= SPECIAL KIND OF DIFFUSION
IMAGE by RIEDELL
See osmosis animation
____________
__________
OSMOSIS
DIFFUSION
Movement of molecules across a_________________ membranefrom ______ concentration to _____Semi-permeable
Higher lower
BUT….What if a cell needs to move _____ or ______ molecules?
http://www.d.umn.edu/~sdowning/Membranes/membraneImages/jpegimages/diffusionmedium.jpg
LARGE POLAR
Facilitated Diffusion_______ proteins help diffusion go
fasterCarrier
MOVIE DIFFUSION ACROSS
THE MEMBRANE (FACILITATED
DIFFUSION)
What if cell needs to move a molecule _________ the CONCENTRATION GRADIENT?_______________
Cell example:Want to put MORE glucoseinto mitochondria when there
isalready glucose in there
(LOWER HIGHER)
Image from: http://www.biologyclass.net/mitochondria.jpg
AGAINST
What if cell needs to move molecules really
_______? (can’t wait for it to diffuse)
Cell example:Movement of Na + & K+ ions required to send nerve signals
http://www.steve.gb.com/images/science/neuron.png
FAST
We need a ____ to ____ molecules across cell
membranes that _______ across by
___________
WAY HELP
can’t go
themselves
FACILITATED DIFFUSION
• No energy required = __________________
• Moves _________ concentration gradient from ________________________
• _____________________ grab molecule, change shape, and flip to other side (Like a revolving door)
• Molecules that move this way in cells:_______________________
PASSIVE
Membrane proteins
GLUCOSE
HIGHER to LOWERDOWN
Facilitated DiffusionAnimation from: http://bio.winona.edu/berg/ANIMTNS/facdifan.gif
Kidspiration by: Riedell
Kinds of ________Transport
•Sodium-Potassium Pump•Endocytosis•Exocytosis
________________________________________
___________________________________
____________________________________
ACTIVE
See a video clip aboutNa+-K+ pump -7D
Sodium (Na+)- Potassium (K+) Pump
Animation from: http://www.lionden.com/cell_animations.htm
See a movie about Na+ - K+ pump
Sodium-Potassium pump
• ___________ 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
ACTIVE
Carrier Proteins
ATP
See a video clip aboutEndo/exocytosis -7E
ENDOCYTOSISTakes substances into cell
• _____________transport (requires __________ from ______)
• Uses small membrane sacs called ______________ to carry substances
ACTIVE
VESICLES
http://www.sirinet.net/~jgjohnso/cell.html
energy ATP
2 KINDS of ENDOCYTOSIS
Takes substances into cellIf taking in:fluid or small 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
PinocytosisPinocytosis
• Called Called “Cell “Cell Drinking”Drinking”
ENDOCYTOSISAnimation from: http://academic.brooklyn.cuny.edu/biology/bio4fv/page/cell-movement.html
http://www.accs.net/users/kriel/chapter%20nine/
PHAGOCYTOSIS
___________ destroying _______White blood cell germs
CalledCalled “Cell “Cell Eating”Eating”
EXOCYTOSISSubstances released outside
of cell
• __________ transport (requires __________)
• Substances move in____________
• Examples in cells:– _________ release packaged proteins
this way
ACTIVE
VESICLES
energy
GOLGI
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
See a Golgi movie
Video: http://www.southtexascollege.edu/tdehne/BC_ShockwaveAnimations/07SWF-TourOfTheCell/07-16-EndomembraneSystem.swf
Endocytosis & Exocytosis
Watch a video clip about endo/exocytosis
Watch a video clip about endo/exocytosis
Choose Screen/Switch programs to view
Videos from: http://www.pleasanton.k12.ca.us/avhsweb/thiel/apbio/notes/chp8/exocytosis_endocytosis.movhttp://trc.ucdavis.edu/biosci10v/bis10v/week2/endocytosis.mov
INSULIN being released by pancreas cells using
exocytosis
http://fig.cox.miami.edu/~cmallery/255/255ion/fig14x26.jpg
What if there is a difference in concentration but solute
molecules can’t move across a membrane?
WATER will move until concentrationreaches equilibrium
VOCAB_____________ = substance that is
dissolved in a solvent to make a solution
_____________ = substance in which a solute is dissolved
SOLUTE
EX:Koolaid powder = soluteWater = solventKoolaid drink = solution
SOLVENT
http://www.makash.ac.il/h_school/hst/hstsb/chem/luach/dissolve.jpg
__________________ = mass of a solute in a given volume of solution
CONCENTRATION
The _______ molecules there are in a given volume the ____________the concentration
Images by Riedell
MOREGREATER
See a video clip aboutOSMOSIS -7B
See an animation Osmosis1
http://faculty.etsu.edu/currie/images/osmosis1.jpg
Animation: http://www.ouhscphysio.org/humanphys/animations/osmosis1.swf
OSMOSIS
HYPERTONIC: Concentration outside cell is ____________________ inside cell
More water leaves cell than enters so cell ____________
GREATER THAN
shrinks
See an animationOSMOSIS 4
Animation from: http://www.ouhscphysio.org/humanphys/animations/osmosis4.swf
Cell in Hypertonic SolutionCell in Hypertonic Solution
CELLCELL
15% NaCL85% H2O
5% NaCL95% H2O
What is the direction of water movement?
ENVIRONMENTENVIRONMENT
OSMOSIS
HYPOTONIC: Concentration outside cell is ________________ inside the cell
More water enters than leaves cell so cellwill ___________________
LESS THAN
Swell and possibly burst
See an animationOsmosis3
Animation from: http://www.ouhscphysio.org/humanphys/animations/osmosis3.swf
Cell in Hypotonic SolutionCell in Hypotonic Solution
CELLCELL
10% NaCL90% H2O
20% NaCL
80% H2O
What is the direction of water movement?
OSMOSIS
ISOTONIC: Concentration outside cell
__________concentration inside cell Water entering = water leaving
so cell _____________________
EQUALS
STAYS THE SAME SIZE
Cell in Isotonic SolutionCell in Isotonic Solution
CELLCELL
10% NaCL90% H2O
10% NaCL
90% H2O
What is the direction of water movement?The cell is at _______________.equilibrium
ENVIRONMENTENVIRONMENT
NO NET NO NET MOVEMENMOVEMENTT
Isotonic Solution
NO NET MOVEMENT OF
H2O (equal amounts entering
& leaving)
Hypotonic Solution
Cell Swells & may burst
Hypertonic Solution
Cell shrivels up
Animal cells
http://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gif
Osmosis in Red Blood CellsOsmosis in Red Blood Cells
IsotonicIsotonic Hypotonic
Hypertonic
Plant cellshttp://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gif
CELL WALL_____ keepsPlant cells from bursting
VACUOLES store WATER
http://www.biology4kids.com/files/cell_vacuole.html
_____________________________ =Pressure exerted by water during osmosis
OSMOTIC PRESSURE
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 youhypotonic
enters
Grocery stores spray water on their veggies to “plump them up”
http://www.painetworks.com/photos/gt/gt0461.JPG
SO WHAT?