Post on 11-May-2015
AWESOME AWESOME OSMOSISOSMOSISAN EGGS-TRA AN EGGS-TRA
SPECIAL EDITIONSPECIAL EDITION
Do you Remember?Do you Remember?
MOVEMENT OF PARTICLE FROM AREA OF HIGHER CONCENTRATION TO LOWER
CONCENTRATION
_If_U__O_
Do you Remember?Do you Remember?
DIFFUSIONMOVEMENT OF PARTICLE FROM AREA OF
HIGHER CONCENTRATION TO LOWER CONCENTRATION
VERY WELL DONE!VERY WELL DONE!
Do you Remember?Do you Remember?
DIFFERENCE IN CONCENTRATION OF A SOLUTE WITHIN A SOLUTION
_O__EN_R_TI_N __AD_E__
Do you Remember?Do you Remember?
COnCENTRATION GRADIENT
DIFFERENCE IN CONCENTRATION OF A SOLUTE WITHIN A SOLUTION
YOU ARE A ROCK STAR!YOU ARE A ROCK STAR!
Do you Remember?Do you Remember?
_A_S__E _R_N_P_R_
MOVEMENT OF MOLECULES ACROSS A CELL MEMBRANE THAT DOES NOT
REQUIRE THE USE OF ENERGY
Do you Remember?Do you Remember?
MOVEMENT OF MOLECULES ACROSS A CELL MEMBRANE THAT DOES NOT
REQUIRE THE USE OF ENERGY
PASSIVE TRANSPORT
Do you Remember?Do you Remember?
What does What does semipermeablesemipermeable
mean when mean when talking about a talking about a
membrane?membrane?
Partially-Permeable Membranes• A partially-permeable membrane will allow certain molecules to pass through it, but not others.
• Generally, small particles can pass through…
Partially permeable membrane
…but large particles cannot
Partially-permeable membraneMore free water molecules on
this side of membrane
Water-solute particle is too large to pass through membrane
Free water molecules diffuse in this direction
DO YOU KNOW?DO YOU KNOW?
Why do you get thirsty after eating something really salty or sweet?
Why do you need to drink water after sweating a
lot?
LET’SLET’SEGGS-PLORE THIS!EGGS-PLORE THIS!
Watch this!Watch this!
What was the membrane What was the membrane semipermeable to in the starch semipermeable to in the starch experiment?experiment?
In the egg experiment was the In the egg experiment was the overall movement of water towards overall movement of water towards the side of a membrane with higher the side of a membrane with higher or lower solute concentration?or lower solute concentration?
Why did water move that way?…why Why did water move that way?…why does ANY molecule move that way??does ANY molecule move that way??
• Osmosis is the diffusion of free water molecules…
•… FROM a region of high concentration of free water molecules…• … TO a region of low concentration of free water molecules…
• …ACROSS a partially-permeable membrane…
…until they are evenly spread out.
OsmosisOsmosis the diffusion of the diffusion of WATERWATER across across
a semi permeable membrane a semi permeable membrane towards the side with higher towards the side with higher solute concentration. solute concentration.
The membrane is not a The membrane is not a barrier to water so it moves barrier to water so it moves to equalize the solute to equalize the solute concentrations either side of concentrations either side of the membrane.the membrane.
Because the membrane is Because the membrane is impermeable to most solutes impermeable to most solutes so the solute cannot diffuse so the solute cannot diffuse to help out with equilibrium.to help out with equilibrium.
So when solutes are So when solutes are concentrated inside or concentrated inside or outside the cell, it will draw outside the cell, it will draw the water in its direction.the water in its direction.
AWESOME OSMOSISAWESOME OSMOSIS
Overview of LabOverview of Lab
Preparation: Preparation: Put egg into vinegar.Put egg into vinegar. Why?Why?
> > Observe egg A and record infoObserve egg A and record info
Carefully rub shell off eggCarefully rub shell off egg
Rinse egg in water and let dryRinse egg in water and let dry
Weigh eggWeigh egg
Put egg into corn syrupPut egg into corn syrup Make Hypothesis!Make Hypothesis!
> > Observe egg B and record infoObserve egg B and record infoRinse egg in water and let dryRinse egg in water and let dryWeigh eggWeigh eggPut egg in tap waterPut egg in tap water
> > Observe egg and record infoObserve egg and record infoLet egg dryLet egg dryWeigh eggWeigh eggData and AnalysisData and Analysis
Overview of LabOverview of Lab
SOLUTION MASS BEFORE
MASS AFTER
DIMENSIONSBEFORE
DIMENSIONS AFTER
CORN SYRUP
94 g 97 g L: 16.5 cmW: 15 cm
L: 15.5 cmW: 13 cm
PURE WATER
102 g 59 g L: 15.5 cmW:13 cm
L: 18 cmW: 16 cm
RESULTSRESULTS
EGGS-TRA EXPERIMENT EGGS-TRA EXPERIMENT
DO THIS!
Draw a picture of a cell Draw a picture of a cell in one of the specific in one of the specific
osmotic solutions, with osmotic solutions, with explanations as to what explanations as to what
is occurring in the is occurring in the molecular level. molecular level.
VISUAL EXAMPLESVISUAL EXAMPLES
Solution is HYPOTONIC to cell.Cell is hypertonic to solution.
Solution is HYPERTONIC to cell.Cell is hypotonic to solution.
Solution is ISOTONIC to cell.Cell is isotonic to solution.
Osmotic solutionsOsmotic solutions
HYPERTONIC SOLUTION HYPERTONIC SOLUTION - - a solution with a a solution with a HIGHERHIGHER solute concentration than what it is compared with.solute concentration than what it is compared with. [Hyper = More than][Hyper = More than]
HYPOTONIC SOLUTION HYPOTONIC SOLUTION - - a solution with a a solution with a LOWERLOWER solute concentration than what it is compared with.solute concentration than what it is compared with. [Hypo = Less than][Hypo = Less than]
ISOTONIC SOLUTIONISOTONIC SOLUTION - - a solution with an a solution with an EQUALEQUAL solute concentration to what it is compared with.solute concentration to what it is compared with. [Iso = The same as][Iso = The same as]
Sugar syrup Egg whitesWater
More concentrated solution OUTSIDE cell
Less concentrated solution inside cell
More concentrated solution INSIDE cell
Less concentrated solution outside cell
Same concentration inside and outside of
cell
(CONTROL)
Egg Osmosis Lab Review
What happened to the egg in the syrup?What happened to the egg in the syrup?
WhyWhy?
This kind of solution is called Hypertonic
Hyper = Too much
Tonic = Solute“Sugar”
“Salt”
The water molecules inside were closer together…
than those outside
So they encountered the membrane more often
What happened to the egg in the pure water?What happened to the egg in the pure water?
WhyWhy??
This kind of solution is called Hypotonic
Hypo = Too little
Tonic = Solute
The water molecules outside were closer together…
than those inside
So they encountered the membrane more often
GET A CLUE!
Cyto = cell
Plasm = fluid, or blood
Cytolysis =
Plasmolysis =
Lysis = to break
cell breaks: (swells and bursts)
fluid breaks: cell shrivels
Which is caused by a hypotonic solution?Which is caused by a hypertonic solution?
Remember this:
Hypertonic =
Hypotonic =
Isotonic =
too much sugar or salt
too little sugar or saltequal sugar or salt
Cytolysis = cell breaks: (swells and bursts)
Plasmolysis = fluid breaks: cell shrivels
Cytolysis does not happen when a cell has cell walls
Plant & bacteria cells develop Turgor Pressure
Turgor = Water pressure inside a cell having walls
Osmosis and Red blood Osmosis and Red blood cellscells
Osmosis Happens!Osmosis Happens! Living things invest a great deal of effort Living things invest a great deal of effort
[Energy] [?] to counteract Osmosis.[Energy] [?] to counteract Osmosis.
Cells use energy to maintain the balanced Cells use energy to maintain the balanced equilibrium of the cell [equilibrium of the cell [homeostasishomeostasis] by actively ] by actively moving molecules across cell membranes thus moving molecules across cell membranes thus avoiding cells “drying out” or “exploding”.avoiding cells “drying out” or “exploding”.
Osmosis is why:Osmosis is why: you get thirsty after eating something really you get thirsty after eating something really
salty or sweet.salty or sweet. why you cant drink seawater when why you cant drink seawater when
shipwrecked.shipwrecked. why you need to drink water after sweating a why you need to drink water after sweating a
lot. lot.
DO YOU KNOW NOW?DO YOU KNOW NOW?
Why do you get thirsty after eating something really salty or sweet?
Why you need to drink water after sweating a
lot?
EVALUATEEVALUATE1.1. Does the water move by osmosis towards the Does the water move by osmosis towards the
hypertonic or hypotonic side of a hypertonic or hypotonic side of a semipermeable membrane?semipermeable membrane?
2.2. In a short sentence explain In a short sentence explain whywhy osmosis osmosis occurs. occurs.
3.3. If a cell is placed in hypertonic solution, will it If a cell is placed in hypertonic solution, will it shrink, swell, or stay the same size?shrink, swell, or stay the same size?
4.4. If a cell is placed in hypotonic solution, will it If a cell is placed in hypotonic solution, will it shrink, swell, or stay the same size?shrink, swell, or stay the same size?
5.5. Write a one paragraph response to the Write a one paragraph response to the following question, in order to apply everything following question, in order to apply everything they learned: If you were stranded at sea, why they learned: If you were stranded at sea, why would it be wise to not drink the salt water?would it be wise to not drink the salt water?
ASSIGNMENTASSIGNMENT
Explore how osmosis applies in food preservation process. Give an example of a
food product.