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.