Download Transporting Molecules

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”
DIFFUSION across a space
Happens anytime there is a _____________
DIFFERENCE
in concentration in one place compared
to another
= Concentration gradient
(________________________)
DIFFUSION across a space
• Molecules move automatically from an
area of _______
Higher concentration to an area
of ________
Lower concentration
• EX: _____________________
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
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?
(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.
OXYGEN
EX: ______________
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
____________________
GREATER THAN inside cell
More water leaves cell than enters
shrinks
so cell ____________
OSMOSIS
Osmosis3
HYPOTONIC:
Concentration outside cell is
________________
LESS THAN inside the cell
More water enters than leaves cell so cell
will ___________________
Swell bigger
OSMOSIS
ISOTONIC:
EQUALS
Concentration outside cell ____________
concentration inside cell
Water entering = water leaving
STAYS THE SAME SIZE
so cell _____________________
Animal cells
= cytolysis
= crenation
http://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gif
http://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gif
Plant cells
No cytolysis/cell wall keeps
it from bursting
= Plasmolysis
VACUOLES store WATER
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 = ____________________
HIGH  LOW
• Moves from ________________________
Carrier Proteins
• _____________________
bind molecule, change
shape, and release it on other side of membrane
Integral
(Carrier proteins are _______________
proteins)
• Molecules that move this way in cells:
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)
HIGH  LOW
• Molecules move from ___________________
• Small passageways for _______
IONS to get through
membrane
• Each ion has own kind of passageway
• Examples in cells: Na+ , Cl- , Ca + + , K +
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
Carrier Proteins to move molecules
• Uses integral ___________________
• Examples in nerve cells:
Na+ is pumped out of cells at same time
K + is taken into cells
+
Na
and K
+
Animation from: http://www.lionden.com/cell_animations.htm
PUMP
ENDOCYTOSIS
Takes substances into cell
• _____________transport
(requires energy from ATP)
ACTIVE
• Uses small membrane sacs to carry substances
= VESICLES
______________
http://www.sirinet.net/~jgjohnso/cell.html
2 KINDS of ENDOCYTOSIS
Takes substances into cell
If taking in:
PINOCYTOSIS
fluid, molecules = ____________________
PHAGOCYTOSIS
large particles or whole cells = __________________
• Examples in cells:
– one celled organisms eat this way
– white blood cells get rid of bacteria this way
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
ACTIVE transport (requires energy)
• __________
VESICLES
• Substances move in____________
• Examples in cells:
– Golgi release packaged proteins
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