s

mOs

O

si

J

b

b

b

A

A

d

A

h

f

t

t

g

Movement of substance into or out

of cellsProcesses

Diffusion OsmosisOsmosis Active Transport

Future !

Past !

Quick Recap• Diffusion is …The net movement of particles from aregion of higher concentration to a

regionof lower concentration. Net

Lesson OutlineLesson Outline

Introduction

What is osmosis

Hyper…Iso and Hypotonic

Misconceptions in osmosis

Conclusion

NIE Productions Presents…

Starring

Ms Hippo as the Bewildering Bouncer

Ms Hips as the Hip and Happening Hippo

Hammy (from over the hedge) as Hyper Hammy!

Once upon a time…

There were 2 clubs in town

HiPpO NiTE!

HIPS dun lieHIPS dun lie

HipPo Nite!

CrOwd r’ usCrOwd r’ us

One was hippo exclusive and the other free for all

Of course the free for all was more popular with

everyone, even the hippos

However, the night goes on with hippos moving about clubs seeing

which is better

Being rather large though, more would have moved to the

exclusive club by the end of the night

One Night When Ms Hips and Hyper Hammy were dating …

HipPo Nite!

HiPpO NiTE!

Don’t even think about it

@!

CrOwd r’ us

HIPS dun lie

Maybe I’ll sneak in!

Hips Only

Wow its so crowded! Come in

sweetie!

There’s too many other Hips

in there!

FREE 4 ALL!

So … from the story

• Do the Hippos stay at one place the whole night?

• Why did Ms Hips decide to move to Hips dun Lie?

• Why couldn’t Hammy enter Hips dun Lie?

Story Concept

2. Net Movement of is from a highly crowded area to a less crowded area

3. Movement across a selective bouncer

1. are moving from club to club throughout

Osmosis Concept

1. Water molecules are always moving about

2. Net movement of WATER MOLECULES (Solvent) from a solution of higher concentration of water to one with lower concentration of water

3. Movement of WATER MOLCULES must be through a PARITALLY PERMEABLE MEMBRANE

Water PotentialInstead of using the word concentration for water…

We use WATER POTENTIAL

- Water potential is the measure of tendency for water to move from one place to another

- Water moves from High Water Potential to Low Water Potential

‘High’ Water

Potential

‘Low’ Water Potential

Osmosis Concept (revised)

1. Net movement of WATER MOLECULES (Solvent) from a solution of higher concentration of water to one with lower concentration of water

2. Movement of WATER MOLCULES must be through a PARITALLY PERMEABLE MEMBRANE

water potentialwater potential

LegendWater

molecule

Solute molecule

Container B (Diluted Solute Solution)

66.6% Water Concentration

33.33% Solute Concentration

Container A (Concentrated

Solute Solution)

20% Water Concentration

80% Solute Concentration

Partially Permeable Membrane

Remember Diffusion? Net Movement of particles down a concentration gradient from an

area of higher concentration to an area of lower concentration!

So wait… ok I know how Osmosis works… but water

moves from

High Water Potential ?

Low Solute Concentration?

Relatively Hypertonic?

Concentrated Solution ?

??????!!

It’s about the Word Play

Concentrated Solution (Sucrose for example)

Low Water Potential

Low concentration of Solvent

High concentration of Solute

Hypertonic compared to B

Dilute Solution

High Water Potential

High Concentration of Solvent

Low Concentration of Solute

Hypotonic compared to A

A B

80% sucros

e

20% water

20% sucrose

80% water

Net

Hypo…Iso…Hyper(for animal systems not plants)

A is hypotonic with respect to

B

A is hypertonic with respect to

B

A and B are isotonic (no net

movement)

A

10% sucrose solution

B

20% sucrose solution

A

20% sucrose solution

B

10% sucrose solution

A

15% sucrose solution

B

15% sucrose solution

Net Net

How to remember?

Censored!

Yes! I’m too fast

and sneaked

in!...

Relatively Hypotonic

(Hippo)

Water movement (Pee)

Relatively Hypertonic

(Hyper Hammy)

Yikes!!!

To Recall…

Semi-Permeable Membrane

A

10% sucrose solution

B

20% sucros

e solutio

n

Solution A is hypertonic solution

Solution B is hypotonic solution

“Osmosis taking place via the uni-

direction movement of water molecules from A

to B”

Spot the errors!

Semi-Permeable Membrane

A

10% sucrose solution

Solution A is hypertonic

Solution B is hypotonic

“Osmosis taking place via the uni-direction movement of water molecules from A to

B”

Spot the errors!

V

V

A

10% sucrose solution

B

20% sucros

e solutio

n

1. Semi-permeable membrane (Partially)

2. This is a hypertonic solution (need to be relative to something)

3. Molecules only move from high water potential to low water potential (It’s the net movement, molecules do not stop moving anyway)

Misconceptions

So in Closing…

1.What are the 2 main concepts of osmosis?

Osmosis is…

1.The net movement of water molecules from a solution of higher water potential to a solution of lower water potential

2.Through a semi-permeable membranepartially

• For animal systems, water molecules will move from a relatively hypotonic solution to a relatively hypertonic solution

• Remember Hippo pee on Hyper Hammy!

Next lesson

Oh I can’t wait!!

1. Importance of Osmosis in…

-Plant Cell

-Animal Cell

2. Active Transport

Thank You!