diffusion osmosis€¦ · following terms: osmosis, diffusion and active transport. what are...

12
What happens if you put a few drops of food coloring in water? Over time, the molecules of color spread out through the rest of the water. When the molecules are evenly spread throughout the space, the water will become an even color. This process of molecules moving from an area where there are lots of molecules to an area where there are fewer molecules is known as diffusion. Diffusion Small molecules can pass through the plasma membrane through a process called diffusion. Diffusion is the movement of molecules from an area where there is a higher concentration (larger amount) of the substance to an area where there is a lower concentration (lower amount) of the substance (Figure below). The amount of a substance in relation to the total volume is the concentration. During diffusion, molecules are said to flow down their concentration gradient, flowing from an area of high concentration to an area of low concentration. Molecules flowing down a concentration gradient is a natural process and does not require energy. Diffusion can occur across a semipermeable membrane, such as the cell membrane, as long as a concentration gradient exists. Molecules will continue to flow in this manner until equilibrium is reached. At equilibrium, there is no longer an area of high concentration or low concentration, and molecules flow equally in both directions across the semipermeable membrane. At equilibrium, equal amounts of a molecule are entering and leaving a cell. Osmosis The diffusion of water across a membrane because of a difference in concentration is called osmosis. Let's explore three different situations and analyze the flow of water. 1. A hypotonic solution means the environment outside of the cell has a lower concentration of dissolved material than the inside of the cell. If a cell is placed in a hypotonic solution, water will move into the cell. This causes the cell to swell, and it may even burst. 2. A hypertonic solution means the environment outside of the cell has more dissolved material than inside of the cell. If a cell is placed in a hypertonic solution, water will leave the cell. This can cause a cell to shrink and shrivel. An isotonic solution is a solution in which the amount of dissolved material is equal both inside and outside of the cell. Water still flows in both directions, but an equal amount enters and leaves the cell. Applications of Osmosis How do marine animals keep their cells from shrinking? How do you keep your blood cells from bursting? Both of these questions have to do with the cell membrane and osmosis. Marine animals live in salt water, which is a hypertonic environment; there is more salt in the water than in their cells. To prevent losing too much water from their bodies, these animals intake large quantities of salt water and then secrete the excess salt. Red blood cells can be kept from bursting or shriveling if put in a solution that is isotonic to the blood cells. If the blood cells were put in pure water, the solution would be hypotonic to the blood cells, so water would enter the blood cells, and they would swell and burst (Figure below). Adapted from: http://www.ck12.org/life-science/Diffusion-in-Life-Science/lesson/Diffusion-MS-LS/? referrer=featured_content

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Page 1: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

Wh

at

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t a

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wa

ter?

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tim

e, th

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of

co

lor

spre

ad

ou

t th

rou

gh

th

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est

of

the

wa

ter.

Wh

en

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ec

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an

are

a w

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ts o

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les

to a

n a

rea

wh

ere

th

ere

are

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kn

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s d

iffu

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Diffu

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Sm

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ure

be

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). T

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re

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to

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co

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ole

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th

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on

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m a

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ow

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gra

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nt

is a

na

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an

d d

oe

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req

uire

en

erg

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cro

ss a

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mip

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me

mb

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ch

as

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ue

to

flo

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an

ne

r u

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qu

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riu

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. A

t e

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er

an

are

a o

f h

igh

co

nc

en

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r lo

w c

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nd

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qu

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in b

oth

dire

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ab

le m

em

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. A

t e

qu

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qu

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am

ou

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of

a m

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re e

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Osm

osi

s

The

diffu

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ec

au

se o

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et's

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thre

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iffe

ren

t si

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an

d a

na

lyze

th

e f

low

of

wa

ter.

1.

A h

yp

oto

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ea

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uts

ide

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ce

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sid

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into

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sw

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ma

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n b

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2.

A h

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ate

r w

ill le

ave

th

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ell.

Th

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ca

use

a c

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to s

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An

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Wa

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still

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dire

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n e

qu

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ave

s th

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Ap

plic

atio

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of

Osm

osi

s

Ho

w d

o m

arin

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nim

als

ke

ep

th

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ells

fro

m s

hrin

kin

g?

Ho

w d

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yo

ur

blo

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lls f

rom

bu

rstin

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Bo

th o

f th

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qu

est

ion

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ave

to

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th

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nim

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live

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lt w

ate

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hic

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a h

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th

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inta

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larg

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ntitie

s o

f sa

lt w

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nd

th

en

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te t

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exc

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Page 2: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

1. 2.

3. 4.

Read It!

Read It!

Read It! Read It!

How can a hypotonic

solution cause a cell to

rupture? Describe this

process as specifically as

you can.

If a plant cell is placed in a solution

and the cell shrivels up, what type

of solution was it placed in? How

do you know?

Describe the process

of diffusion.

Do water molecules

leave or enter a cell in

an isotonic solution?

Page 3: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

1. 2.

3. 4.

Watch It!

Watch It!

Watch It! Watch It!

Go to the following Video:

http://tinyurl.com/ATbrainpop

How do transport proteins move

substances across membranes?

A. They move inside the membrane,

carrying the substance.

B. They change shape

C. They rip open a temporary hole in

the membrane

D. They increase the concentration

gradient inside the cell.

The cell membrane is semi-

permeable. What does permeable

mean?

A. Extremely thick

B. Extremely thin

C. Things can penetrate/get

through it

D. Able to be broken

What is the difference between active

and passive transport?

A. Active transport requires energy;

passive transport does not

B. Active transport moves molecules

across cell membranes; passive

transport does not

C. Active transport involves oxygen and

water molecules; passive transport

does not

Page 4: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

5.

7. 8.

Watch It!

6.

Watch It!

Watch It! Watch It!

What might happen if the cell didn’t have any ATP?

A. It would not have enough energy to carry out

active transport.

B. Its transport proteins would be made of

carbohydrates instead.

C. Its cell membrane would no longer be semi-

permeable

D. Its concentration gradient would be steeper.

What can you infer about the

membrane of a vesicle or a

vacuole?

A. It is made out of transport

proteins.

B. It is made out of water molecules

C. It is made out of the same

substance as the cell membrane

D. It is made out of cellulose

If you were looking for transport

proteins, where would you find

them?

A. Inside a cell’s nucleus

B. Lodged within a cell’s

membrane

C. Inside a cell’s cytoplasm

D. Inside a cell’s endoplasmic

The natural spreading of particles

through a liquid or gas is called:

A. Dilution

B. Diffusion

C. Differentiation

D. Fusion

Page 5: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

1. 2.

3. 4.

Explore It!

Explore It!

Explore It! Explore It!

The Osmosis Gizmo™: The red

square represents a cell a solution

of purple solute (like salt) particles

dissolved in green solvent (like

water) particles. Press Play and

observe. Answer the questions on

your Lab Sheet.

Go to the Osmosis Gizmo.

Follow the directions.

Go to the Diffusion

Gizmo. Follow the

directions:

Get the Gizmo ready:

Click Reset. Set the Initial cell volume

to 40%.

Observe: Use the Solute outside slider to

change the concentration of solute

particles outside the cell. Click Play.

In each case, focus on whether the

cell gets bigger or smaller.

Answer the questions on your lab sheet.

Page 6: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

5. 6.

7. 8.

Explore It!

Explore It!

Explore It! Explore It!

Click Pause ( ), and select the

GRAPH tab. What does the graph

tell you about the number of

particles in region A? Answer the

question on your lab sheet.

Select the BAR CHART tab,

and observe the chart

for a few minutes.

Answer the question on

your Lab Sheet.

Smells are carried by tiny particles that

move through the air. The Diffusion

Gizmo™ shows gas particles in a

chamber that is divided into two

regions by a partial wall. Click Play

( ) and observe. Answer the

questions on your lab sheet.

Get the Gizmo ready:

Click Reset ( ).

Set the Wall to 100%.

Observe: Set the temperature

(Temp.) to 100 K, and press Play.

Observe the motion of particles.

Click Reset. Then set the

temperature to 600 K, click Play,

and observe.

Page 7: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

1. 1.

Research It!

Illustrate It!

Draw a picture to represent

the meaning of each of the

following terms: osmosis,

diffusion and active

transport.

What are endocytosis

and exocytosis?

How are they

used in cells?

1.

Write It!

Scan the QR code to access your writing

prompt. Use C-E-R

to defend your

answer.

1.

Assess It!

Open the Socrative app or go to

socrative.com to complete the

assessment.

Page 8: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

1.

Organize It!

Match each scenario

to the type of cellular

transport that is taking

place.

Osmosis

Diffusion

Active

Transport

Page 9: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

Wa

ter

mo

ve

s o

ut

of

the

ce

lls o

f a

sa

ltw

ate

r fish

an

d in

to

the

oc

ea

n.

Oxyg

en

mo

ve

s fr

om

th

e lu

ng

s in

to t

he

b

loo

dst

rea

m.

So

diu

m is

pu

mp

ed

o

ut

of

a n

erv

e c

ell.

Y

ou

sm

ell

the

d

elic

iou

s sc

en

t o

f fr

esh

-ba

ke

d

co

okie

s b

efo

re

yo

u e

ve

n e

nte

r th

e k

itc

he

n.

An

am

oe

ba

e

ng

ulfs

a p

art

icle

o

f fo

od

.

Wa

ter

en

ters

th

e

roo

ts o

f p

lan

ts

fro

m t

he

so

il.

A ly

soso

me

dig

est

s fo

od

pa

rtic

les

an

d

the

n u

ses

exo

cyto

sis

to g

et

rid

of

wa

ste

.

Pa

rtic

les

tha

t a

re

too

big

pa

ss

thro

ug

h s

pe

cia

l

ca

rrie

r p

rote

ins

mo

vin

g f

rom

a h

igh

co

nc

en

tra

tio

n t

o a

low

co

nc

en

tra

tio

n

Hyd

rog

en

io

ns

are

pu

mp

ed

fro

m

an

are

a o

f lo

w

co

nc

en

tra

tio

n t

o

an

are

a o

f h

igh

co

nc

en

tra

tio

n.

Wa

ter

mo

ve

s fr

om

a

n a

rea

of

low

sa

lt

co

nc

en

tra

tio

n

tow

ard

s a

n a

rea

th

at

is m

ore

sa

lty.

Page 10: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

The

diffu

sio

n o

f w

ate

r a

cro

ss a

se

lec

tiv

ely

p

erm

ea

ble

m

em

bra

ne

.

Re

qu

ire

s th

e

use

of

the

ce

ll’s

en

erg

y.

The

mo

ve

me

nt

of

pa

rtic

les

fro

m

are

a o

f lo

w

co

nc

en

tra

tio

n t

o

an

are

a o

f h

igh

er

co

nc

en

tra

tio

n.

Ro

ots

ce

lls

pu

mp

m

ine

rals

in

fro

m t

he

so

il.

Do

es

no

t re

qu

ire

th

e

ce

ll’s

en

erg

y.

So

me

on

e s

pra

ys

air f

resh

en

er

ac

ross

th

e r

oo

m

an

d e

ve

ntu

ally

yo

u c

an

sm

ell

it

ev

ery

wh

ere

.

Wh

at

is h

ap

pe

nin

g

with

th

e g

ree

n

pa

rtic

les

fro

m t

he

b

ott

le?

The

mo

ve

me

nt

of

pa

rtic

les

fro

m a

n a

rea

of

hig

h

co

nc

en

tra

tio

n t

o a

n a

rea

o

f lo

w

co

nc

en

tra

tio

n.

Wh

at

pro

ce

ss w

ou

ld h

elp

th

e v

ac

uo

les

refill

wh

en

yo

u w

ate

r th

e p

lan

t?

Page 11: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

Input Stations

Explore It!

Task Card 2:

1. Which particles can pass through the cell membrane?

2. Which particles cannot pass through the cell membrane?

3. Click Reset ( ), and then click Play again. What do you notice

about the size of the cell?

Task Card 3:

1. In what situation does the cell get larger ?

2. In what situation does the cell get smaller?

Task Card 5:

1. Describe the motion of the gas particles:

2. Over time, what is happening?

Task Card 6:

1. After the first 30 seconds or so, how much do the numbers of

particles in each region change?

FACT: When the numbers don’t change much, the particles are said

to be in dynamic equilibrium.

Explore It!

Task Card 7:

1. What does the graph tell you about the number of

particles in region A?

Task Card 8:

1. How does the temperature of the gas relate to the motion of

the particles?

Read It!

Task Card 1:

Task Card 2:

Task Card 3:

Task Card 4:

Page 12: Diffusion Osmosis€¦ · following terms: osmosis, diffusion and active transport. What are endocytosis and exocytosis? How are they used in cells? 1. Write It! Scan the QR code

Watch It!

Output Stations

Write It!

Use Claim, Evidence and Reasoning

Task Card 1:

Illustrate It!

Task Card 1:

Assess It! (See teacher for Socrative Code)

Organize It!

Reflection: How did you do? What did you find easy? What

mistakes did you make?

Teacher Initials:

___________2.

___________3.

___________4.

___________5.

___________6.

___________7.