Download concentration - Tenafly High School

Concentration Gradient,
Osmosis, and
Diffusion
What is concentration?
Not this concentration!
What is a Gradient?
Concentration Gradient
Evenly Concentrated
Concentration gradient is when the substance stays in one area more, than
in another area (unequal distribution).
Unevenly Concentrated
The process of diffusion and osmosis help to even out the concentration
gradient.
Diffusion!

Diffusion is the movement of PARTICLES or
substances from an area higher concentration to
an area of lower concentration to reach
equilibrium.

What is Equilibrium?????
Diffusion
Diffusion
Osmosis!

Is when WATER molecules go through a
semi-permeable membrane (cell membrane)
from an area of higher concentration to an
area of lower concentration.
Osmosis & Diffusion

How are they similar????

How are they different?
Solutions & Water
Water will move in and out of a cell to
find balance.
This balance is also called equilibrium.
Types of Solutions
Isotonic Solution
Hypotonic Solution
Hypertonic Solution
These solution all focus on the movement
of WATER. The water will move from HIGH
to LOW concentration.
Video (2:04)
Isotonic Solution
•A solution has an equal amount of solute inside
and outside of the cell.
•When a cell is placed in an isotonic solution, the
water diffuses into and out of the cell at the same
rate.
Hypertonic Solution
• A solution where there is more solute (particles)
outside the cell than inside.
• When a cell is placed in a hypertonic solution, the
water diffuses out of the cell, causing the cell to
shrivel up.
Hypotonic Solution
• A solution where there is more solute (particles)
inside the cell than inside.
• When a cell is placed in a hypotonic solution, the
water diffuses into the cell, causing the cell to
swell and possibly explode
Hypotonic Plant Cells
Water will fill the cell.
It will NOT explode.
The cell wall prevents the
plant cell from rupturing.
Hypotonic Animal Cells
Water will fill the cell.
It will explode if it gets too full.
Animal cells do not have the
structure that the cell wall provides.
Additional Video
Part 2
then
Diffusion
http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
http://www.biologycorner.com/resources/diffusion-animated.gif
In Diffusion molecules move
FROM
A LOT
_______“where
there’s _______”
____“where
there’s _______”
to
NOT
DIFFUSION across a space
Happens anytime there is a
DIFFERENCE
__________
in concentration in one
place compared to another
Concentration gradient
= ________________________
DIFFUSION
DOWN
Molecules move automatically _______
the
from
concentration gradient _______
an area of
Higher
_______
concentration ____
to
an area of
Lower
________
concentration
• EXAMPLES
Strong perfume
Someone baking cookies
DIFFUSION
Diffusion continues until the concentration is
equal everywhere
________________
in space
= ________________________
Equilibrium
http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png
DIFFUSION IN YOUR CELLS :
Take a deep breath . . .
DIFFUSION automatically moves oxygen from
HIGHER concentration (in lungs)
to a LOWER concentration (in blood)
CO2 automatically moves
from 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
http://bioweb.wku.edu/courses/Biol22000/10Biomembranes/images/membrane.gif
DIFFUSION
PASSIVE _
• No energy required = ______
• Moves _______ concentration gradient
from higher to lower.
DOWN
• Works for any molecules that can pass through
the membrane .
• Example of molecules that move this way in
cells:
OXYGEN
CARBON DIOXIDE
________
& ____________
What does the word facilitate mean?
FACILITATED DIFFUSION
membrane proteins to help
uses _______________
molecules cross a membrane.
2 kinds of proteins help:
Carriers
Channels
_________
& ____________
Animations from: http://bio.winona.edu/berg/ANIMTNS/facdifan.gif
http://www2.uic.edu/~myilma1/ionchannel.gif
Facilitated Diffusion with
CARRIER PROTEINS
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
http://www.gobananas.co.uk/edinburgh-stag-party/enquiry/index.htm
FACILITATED DIFFUSION
with CHANNELS
http://bio.winona.edu/berg/ANIMTNS/voltgate.htm
Membrane
proteins
create a
tunnel through
which molecules
can pass
Passive Transport
•Passive Transport moves substances from
high to low concentration
•Passive Transport does NOT require
any energy to move substances
Examples include: osmosis, diffusion, facilitated diffusion
A problem for CELLS
Diffusion only moves molecules
from high concentration to low
concentration and this happens
very slowly.
From Low to High
What if cell needs to move a
AGAINST the
molecule _________
CONCENTRATION GRADIENT?
(LOWER  HIGHER)
_______________
Cell example:
Want to put MORE glucose
into mitochondria when there is
already glucose in there
Image from: http://www.biologyclass.net/mitochondria.jpg
What if cell needs to move
FAST
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
WAY to
Cells need a ____
HELP molecules across
____
cell membranes that
can’t go across by
_______
themselves
___________.
The way is Active Transport
Active Transport
•Active Transport DOES require energy to
move substances
•It moves substances from LOW to HIGH
concentration
Types of Active Transport
• PUMPS
________________________________________
•Sodium-Potassium
__________________________________
•Proton
________________________________
•Vesicles
___________________________________
•Endocytosis
________________________________
Phagocytosis
________________________________
•Exocytosis
Na+ and K
+
PUMP
http://www.lionden.com/cell_animations.htm
See a movie
about Na+ - K+ pump
PROTON PUMP
Moves
Protons
across
membrane
+
H
= ___ ions
See a movie
proton pump
ACTIVE TRANSPORT
with VESICLES
VESICLES
___________
are small membrane sacs that
pinch off of cell membranes used by cells for
transporting molecules
Used for transporting molecules:
ENDOCYTOSIS
If entering the cell = ______________
EXOCYTOSIS
If exiting the cell = _______________
http://academic.brooklyn.cuny.edu/biology/bio4fv/page/cell-movement.html
http://academic.brooklyn.cuny.edu/biology/bio4fv/page/exocy.htm
ENDOCYTOSIS
http://academic.brooklyn.cuny.edu/biology/bio4fv/page/cell-movement.html
Protist eating
another
http://www.accs.net/users/kriel/chapter%20nine/
2 KINDS of ENDOCYTOSIS
for taking substances into cell
If taking in:
PINOCYTOSIS
fluid or small molecules =_________________
PHAGOCYTOSIS
large particles or whole cells =______________
Animation from: http://academic.brooklyn.cuny.edu/biology/bio4fv/page/endocytb.htm
PHAGOCYTOSIS
White blood cell
germs
___________ destroying _______
WHITE BLOOD CELL
ENGULFING BACTERIA
(Phagocytosis)
http://fig.cox.miami.edu/~cmallery/255/255ion/fig14x28.jpg
Video: http://www.southtexascollege.edu/tdehne/BC_ShockwaveAnimations/07SWF-TourOfTheCell/07-16-EndomembraneSystem.swf
GOLGI BODIES USE EXOCYTOSIS
Animation from: http://www.franklincollege.edu/bioweb/A&Pfiles/week04.html
See a Golgi movie
Osmosis VOCAB
_____________ = substance
that is dissolved in a solvent
to make a solution
SOLUTE
_____________ = substance in which a solute
is dissolved
SOLVENT
Use new vocab to make Kool-aid
Kool-Aid Powder
Solute = ______________
Water
Solvent = ____________
solution
Kool-aid drink = ______________
http://www.makash.ac.il/h_school/hst/hstsb/chem/luach/dissolve.jpg
Solute Concentration
Lower outside
than inside
Equal outside
and inside
HYPOTONIC
ISOTONIC
Greater outside
than inside
HYPERTONIC
VACUOLES store WATER
http://www.biology4kids.com/files/cell_vacuole.html
OSMOTIC PRESSURE
_____________________________ =
Pressure exerted by the movement of water
during osmosis
http://www.stchs.org/science/courses/sbioa/metenergy/aplantturgor.gif
Plant cells
CELL
WALL
_____
keeps
plant cells from bursting
___________
= PLASMOLYSIS
Grocery stores spray water on their
veggies to “plump them up”
http://www.painetworks.com/photos/gt/gt0461.JPG
http://www.stchs.org/science/courses/sbioa/metenergy/bloodcells.gif
Animal cells
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