Bio Chapter 7.3 Notes

Cellular Movement

I.Background Information

A. Solution- a mixture in which the solute

(molecules being dissolved) never settle out

in the solvent (water).

B. In a 25% Koolaid solution, how much

water is there?

http://ajacksonian.blogspot.com/2007_04_01_archive.htmlhttp://isillybob.blogspot.com/

http://awesomeist.blogspot.com/2009_04_01_archive.html

http://www.docbrown.info/page04/4_73calcs06brmv.htm

http://en.wikipedia.org/wiki/Concentration

http://water.me.vccs.edu/courses/env211/lesson8_3.htm

C. Every living cell contains a liquid interior

(cytoplasm) and is surrounded by a liquid

(fluid that baths your cells).

The concentration of a solution is defined

as the

1. volume of solute in a given

mass of solution.

2. mass of solute in a given

volume of solution.

3. mass of solution in a given

volume of solute.

4. volume of solution in a given

mass of solute.volu

me o

f solu

te in

a gi..

.

mass

of s

olute

in a g

iven...

mass

of s

olutio

n in a

giv..

volum

e of s

olutio

n in a

...

0% 0%0%0%

20Answer Now

II. Homeostasis

A. Process where the cell/organism tries to

maintain a constant internal environment.

1.E.g. Body temperature, blood sugar, and

body fluids.

http://www.mhhe.com/biosci/esp/2002_general/Esp/default.htm

http://scienceblogs.com/clock/2006/06/bio101_lecture_7_physiology_co_1.php

The plasma membrane (cell membrane) is

________.

1. a single-layered membrane that

surrounds the nucleus of the cell

2. a double layer of protein enclosing

the plasma

3. the phospholipid bilayer surrounding

the cell

4. a membrane composed of tiny shelves

or cristae

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B. Cells maintain homeostasis by controlling

what enters and leaves the cell via the cell

(plasma) membrane.

1. It is selectively (semi-) permeable – it allows

some molecules to move in/out of the cell

http://bioserv.fiu.edu/~walterm/FallSpring/cell_components/cell_talk.htm

Active Art Diffusion

Which of the following is a function of the

cell membrane?

1. breaks down lipids,

carbohydrates, and

proteins from foods

2. stores water, salt, proteins,

and carbohydrates

3. keeps the cell wall in place

4. regulates which materials

enter and leave the cellbre

aks dow

n lipid

s, ca

rb...

store

s wate

r, sa

lt, p

rote

in..

keeps the ce

ll wall

in p

lace

regu

late

s which

mate

rial..

.

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20Answer Now

The model describing the structure of the

cell membrane is known as __________.

1. the “sandwich” model.

2. the “fabric” model.

3. the “mosaic tile” model.

4. the “fluid mosaic” model.

the “s

andwich

” model.

the “f

abric” m

odel.

the “m

osaic

tile” m

odel.

the “f

luid

mosa

ic” m

odel.

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Answer Now 18

III. Cell Membrane

A. Structure: “Fluid Mosaic Model” – parts are

not in fixed positions, they are free to “float”

along the bilayer (sea of fat)

Label: Glycoprotein, Glycolipid, Integral

protein, Peripheral protein

AND Cholesterol

1 2

34

5

1. Double bilayer of lipids with imbedded,

dispersed proteins

2. Bilayer consists of phospholipids,

cholesterol, and glycolipids

a. Glycolipids are lipids with bound

carbohydrate, found in outer membrane

Phospholipids ________.

1. are exclusively hydrophilic molecules

2. contain polar tails and nonpolar head

groups

3. are both hydrophilic and hydrophobic

in nature

4. form the lipid bilayer, with tails

directed to the outside

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b. Phospholipids have two hydrophobic (water

hating) tails and a hydrophilic (water loving)

head

i. The center section of the lipid bilayer is

hydrophobic, either side of the bilayer (in/out

of the cell) is hydrophilic.

ii. The regions of the protein embedded in the

bilayer are hydrophobic; the regions of

protein exposed to the internal/external

environment of the cell are hydrophilic.

Polar region of phospholipid

A. A

B. B

C. C

D. D

E. E

A B C D E

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Answer Now15

a. Polar molecules have a difference in

charges; therefore attract ions like Na+, Ca+2,

and K+

Dissolving Salt in Water-Physical Animation:

http://www.yellowtang.org/animations/dissolvin

g_salt.swf

Simple diffusion may involve the

movement of ______________________

through the plasma membrane down a

concentration gradient.

1. small polar molecules

2. small nonpolar molecules

3. large polar molecules

4. large nonpolar molecules

small p

olar m

olec

ules

small n

onpo

lar m

olec

ules

large po

lar m

olec

ules

large no

npolar m

olec

ules

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20Answer Now

3. Draw a single phospholipid (label: head, tails,

hydrophobic and hydrophilic end); Draw the

phospholipd bilayer membrane.

Which of the following is a principle of the fluid

mosaic model of cell membrane structure?

1. Phospholipids form a bilayer that is largely

impermeable to water-soluble molecules.

2. Phospholipids consist of a polar head and a

nonpolar tail made of three fatty acid

chains.

3. The lipid bilayer is a solid at body

temperature, thus protecting the cell.

4. All proteins associated with the cell

membrane are contained in a fluid layer on

the outside of the cell.

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30Answer Now

Which of the following would not be a

constituent of a plasma membrane?

1. glycolipids

2. messenger RNA

3. glycoproteins

4. phospholipids

glycolip

ids

mess

enger RNA

glycopro

tein

s

phospholip

ids

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Answer Now 18

4. Functions of Membrane Proteins – molecules

floating in sea of fat allow:

a. Transport

i. Carrier Proteins – bind to a substance and

transport it across the membrane “down” the

concentration gradient (High to low)

ii. Channel Proteins – form pores or

passageways for molecules to move through

the membrane “down” the concentration

gradient

b. Enzymatic activity

c. Receptors for signal transduction

i. Contact signaling – important in normal

development and immunity

ii. Electrical signaling

– voltage-regulated

“ion gates” in nerve

and muscle tissue

iii. Chemical signaling –

neurotransmitters

bind to chemically

gated channel-linked

receptors in nerve and

muscle tissue

d. Intercellular adhesion (CAM’s)

i. Anchor cells to the extracellular matrix

ii. Assist in movement of cells past one another

iii. Rally protective white blood cells to injured

or infected areas

e. Cell-cell recognition – identify the cell

Identification "tags" for the cell

A. A

B. B

C. C

D. D

E. E

A B C D E

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15

f. Attachment to cytoskeleton and extracellular

matrix

Which of the following is a function of a

plasma membrane protein?

1. circulating antibody

2. molecular transport

through the membrane

3. forms a lipid bilayer

4. oxygen transport

circu

latin

g antib

ody

mole

cula

r tra

nsport

th...

form

s a li

pid b

ilaye

r

oxyge

n transp

ort

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IV. Transport across the membrane

A. Label Diagram

B. Phospholipid bilayer prevents large

molecules (like sugars and amino acids) from

passing through the membrane.

C. Water molecules are small enough to

diffuse across the lipid bilayer.

The cell membrane contains channels and

pumps that help move materials from one

side to the other. What are these channels

and pumps made of?

1. carbohydrates

2. lipids

3. bilipids

4. proteins

carb

ohydrate

slip

ids

bilipid

s

prote

ins

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18Answer Now

http://torresbioclan.pbworks.com/w/page/22377235/Spikefish%20Cell%20Wall

http://micro.magnet.fsu.edu/cells/plants/cellwall.html

http://www.sigmaaldrich.com/life-science/metabolomics/enzyme-explorer/learning-center/lysing-enzymes.html

Cell Wall vs.

Cell Membrane

Composition

Unlike a cell wall, a cell membrane

1. is composed of a lipid bilayer.

2. provides rigid support for the

surrounding cell.

3. allows most small molecules

and ions to pass through

easily.

4. is found only in plants, fungi,

algae, and many prokaryotes.

is co

mpose

d of a

lipid

bil.

..

provid

es rigi

d support

fo...

allow

s most

small m

olecu

...

is fo

und only

in p

lants

, f...

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20Answer Now

You will NOT find a cell wall in which of

these kinds of organisms?

1. plants

2. animals

3. fungi

4. all of the above

plants

animals

fungi

all of t

he above

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V. Passive Processes – (No energy required)

A. Diffusion- Random mixing of particles in

a solution as a result of the particle’s kinetic

energy

http://staff.jccc.net/aalarabi/Plasma-membrane.ppt

Diffusion is the movement of molecules from

1. an area of low concentration

to an area of high

concentration.

2. an area of high

concentration to an area of

low concentration.

3. an area of equilibrium to an

area of high concentration.

4. all of the abovean a

rea o

f low

conce

ntra...

an are

a of h

igh co

ncentr.

..

an are

a of e

quilibriu

m to

...

all of t

he above

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1. More molecules move randomly from an

area of high concentration to an area of low

concentration (down their concentration

gradients)

2. It’s the solute that moves in and out of the

cell if it can pass through the plasma

membrane

3. The following conditions affect the rate of

diffusion (how fast the solute moves across

the membrane):

a. The greater the difference in concentration

between the 2 sides of the membrane, the

faster the rate of diffusion

If a substance is more highly concentrated

outside the cell than inside the cell and the

substance can move through the cell membrane,

the substance will

1. move by diffusion from inside the cell

to outside.

2. remain in high concentration outside

the cell.

3. move by diffusion from outside to

inside the cell.

4. cause water to enter the cell by

osmosis.

move

by d

iffusio

n from

i...

rem

ain in

hig

h conce

ntra.

..

move

by d

iffusio

n from

o...

cause

wate

r to e

nter t

he ...

0% 0%0%0%

25Answer Now

b. The higher the temperature, the faster the

rate of diffusion

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter2/kinetic_airmol.htmlhttp://tannerm.com/temperature.htm

c. the larger the size of the diffusing substance,

the slower the rate of diffusion

http://www.advancedrenaleducation.com/AllAboutDialysis/Hemodiaylsis/ModalitiesofTherapy/ExtracorporealModalities/HemofiltrationModality/tabid/199/Default.aspx http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=eurekah&part=A75995

d. an increase in surface area, increases the rate

of diffusion

http://www.sparknotes.com/health/digestion/section2.rhtml

e. Greater diffusion distance, slower rate of

diffusion

http://arditobook.pbworks.com/Diffusionhttp://www.jpp.krakow.pl/journal/archive/1207/articles/13_article.html

Which of the following statements is

correct regarding diffusion?

1. The rate of diffusion is independent of

temperature.

2. The greater the concentration gradient,

the faster the rate of diffusion.

3. Molecular weight of a substance does

not affect the rate of diffusion.

4. The lower the temperature, the faster the

diffusion rate

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4. When the molecules are equal, equilibrium

has been reached

http://www.advancedrenaleducation.com/PeritonealDialysis/KineticPrinciples/BasicPrinciplesofPD/PhysiologyofthePeritoneum/tabid/151/Default.aspx

5. Indicate the direction of solute movement by

drawing an arrow in the direction of flow for

each diagramor

http://www.indiana.edu/~phys215/lecture/lecnotes/diff.html

When the concentration of molecules on both

sides of a membrane is the same, the molecules

will1. move across the membrane to

the outside of the cell.

2. stop moving across the

membrane.

3. move across the membrane in

both directions.

4. move across the membrane to

the inside of the cell.m

ove a

cross

the m

embra

..

stop m

oving a

cross

the...

move

acr

oss th

e mem

br...

move

acr

oss th

e mem

bra..

0% 0%0%0%

20Answer Now

What do you already know?

The diffusion of water across a selectively

permeable membrane is called

1. osmotic pressure.

2. osmosis.

3. facilitated diffusion.

4. active transport.

osmotic

pre

ssure

.

osmosis

.

facil

itate

d diff

usion.

activ

e tran

sport.

0% 0%0%0%

18Answer Now

B. Osmosis - Net movement

(diffusion) of water

through a semi-permeable

membrane from an area of

high water concentration to

an area of low water

concentration

1. Water is most

concentrated

where there is the

least solute

concentration.

2. Water moves to

concentrated

solutions (high

solute

concentrations).

3. Only occurs if membrane is permeable to

water but not to certain solutes

4. Indicate the direction of water movement by

drawing an arrow in the direction of flow

5. Tonicity – how a solution affects cell

volume

a. Isotonic – solutions with the same solute

concentration as that of the cytosol (the

concentration of solutes if equal inside and

outside the cell)

b. Hypertonic – solutions having greater solute

concentration than that of the cytosol (the

concentration of solutes is greater outside the

cell than it is inside)

i. In plant cells, the central vacuole loses water

and the cells shrink, causing wilting.

ii. In animal cells, the cells also shrink.

c. Hypotonic – solutions having lesser solute

concentration than that of the cytosol (the

concentration of solutes is greater inside the

cell than it is outside)

ii. In plants—the central vacuole fills and the

plants are rigid (but the cell wall keeps it from

bursting)

iii. In animals—the cell could lyse (burst) unless

certain organelles pump water out quickly!

6. Osmotic Pressure - Pressure created by

osmosis (pg. 186)

a. Cells are filled with sugars, salts, proteins,

and other molecules which cause a pressure

to build up on the hypertonic side of the

membrane (or inside the cell).

b. If a cell is placed in fresh water, water will

rush into the cell causing is to swell and burst

(Lyse).

c. If this is true, why aren’t your cells expanding

and exploding right now??????

i. Our cells are bathed by blood, which is

isotonic with the fluid in our cells. This

means that the solute concentration inside the

cell is the same as that in the blood.

If the concentration of solutes in a cell is

less than the concentration of solutes in the

surrounding fluid, then the extracellular

fluid is said to be:

1. hypertonic.

2. hypotonic.

3. isotonic.

4. stable.

hyperto

nic.

hypoto

nic.

isoto

nic.

stable

.

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If cells are placed in a hypertonic solution

containing a solute to which the membrane is

impermeable, what could happen?

1. The cells will swell and ultimately burst.

2. The cells will lose water and shrink.

3. The cells will shrink at first, but will later

reach equilibrium with the surrounding

solution and return to their original

condition.

4. The cells will show no change due to

diffusion of both solute and solvent.

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25

Resources\Resources 7-

3\ActiveArt\osmosis_index.html

An animal cell that is surrounded by fresh

water will burst because the osmotic

pressure causes

1. water to move into the cell.

2. water to move out of the cell.

3. solutes to move into the cell.

4. solutes to move out of the cell.

wate

r to m

ove into

the ce

ll.

wate

r to m

ove out o

f the...

solu

tes t

o move

into

the ..

.

solu

tes t

o move

out o

f t..

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20Answer Now

Which of the following statements about the red

blood cells in Figure 7.02 beaker A is true?

1. There has been no net

water movement.

2. There has been a net flow

of water out of the cell.

3. There has been a net flow

of water into the cell.

4. Pinocytosis has occurred

20Answer NowTh

ere h

as been

no n

et wat

..

Ther

e has b

een a

net

flow

o...

Ther

e has b

een a

net

flow

o...

Pinocy

tosis

has

occ

urred

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Which of the following statements about the red

blood cells in Figure 7.02 beaker B is true?

1. These red blood cells have

shrunken in response to a

hypertonic external solution.

2. These red blood cells have

shrunken in response to a

hypotonic external solution.

These re

d blo

od cells

hav..

.

These re

d blo

od cells

ha..

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C. Facilitated Diffusion – Transport Proteins

with in the membrane make it easier for certain

molecules to enter the cell

Facilitated Diffusion

Protein

channel

Glucose

molecules

http://anatomy.iupui.edu/courses/histo_D502/D502f04/lecture.f04/cell.f04/cellf04.html

1. Solutes move down

their concentration

gradients

2. Carrier proteins allow large molecules (like

sugars and amino acids) to cross the

membrane

3. Channel proteins provide a

“safe” crossing for ions across

the cell membrane

a. Ion channels can contain

“gates” that can open or close

depending on internal/external

conditions of the cell

i. This allows the cell to control

when ions can enter/exit the

cell.

The process by which molecules diffuse

across a membrane through protein

channels is called

1. active transport.

2. endocytosis.

3. facilitated diffusion.

4. osmosis.

activ

e tran

sport.

endocyto

sis.

facil

itate

d diff

usion.

osmosis

.

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20Answer Now

VI. Active Processes - (energy required –ATP)

A. Active Transport - molecules moved across

membrane from low concentrations to high

concentrations (“up” their concentration

gradients) with the help of membrane

proteins

Molecule to be carried

Active

Transport

1. Types of Active Transport

a. Primary active transport – hydrolysis of

ATP, phosphorylates the transport protein

causing conformational change (change of

shape)

b. Secondary active transport – use of an

exchange pump (such as the Na+-K+ pump)

indirectly to drive the transport of other

solutes

Sodium-Potassium

Exchange Pumphttp://highered.mcgraw-

hill.com/sites/0072437316/student_view0/chapte

r6/animations.html

i. The sodium potassium pump (Na+-K+) moves

(1) 3 sodium ions out of the cell

(2) 2 potassium ions into the cell

(3) Since both ions are positive (+) the net

charge on the inside of the plasma membrane

becomes negative (-)

(4) The difference in

charge is important

in the conduction of

electrical impulses

(neurons)

The sodium-potassium pump

1. pumps Na+ and K+ out of the

cell.

2. pumps Na+ and K+ into the

cell.

3. pumps Na+ into and K+ out of

the cell.

4. pumps Na+ out of and K+ into

the cell.pum

ps Na+ a

nd K+ o

ut o...

pumps N

a+ and K

+ into

t..

pumps N

a+ into

and K

+ ...

pumps N

a+ out o

f and K

+...

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Answer Now 20

When movement of Na+ ions down their

concentration gradient drives the transport

of other substances across the cell

membrane, it is called___________.

1. primary active transport

2. secondary active transport

3. vesicular transport

4. pumping

primary

act

ive tr

ansp

ort

seco

ndary a

ctive

transp

ort

vesicula

r tra

nsport

pumpin

g

0% 0%0%0%

Answer Now 20

Osmosis does not involve

1. a selectively permeable

membrane

2. a difference in solvent

concentration

3. diffusion

4. active transport

a sele

ctiv

ely perm

eable...

a diff

erence

in so

lvent c

...

diffusio

n

activ

e tran

sport

0% 0%0%0%

Answer Now 20

http://www.biologie.uni-hamburg.de/b-online/library/micro229/terry/229sp00/lectures/nutrition.html

Resources\Resources 7-

3\ActiveArt\active_transoirt_index.html

Passive membrane transport processes

include ________.

1. movement of water from an area of low

concentration to an area of high

concentration

2. consumption of ATP

3. movement of a substance down its

concentration gradient

4. the use of transport proteins when

moving substances from areas of low to

high concentration

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Answer Now25

2. Types of Vesicular Transport-transport of

large particles and macromolecules across

plasma membranes

a. Endocytosis - surrounding a substance with

some of the plasma membrane and then,

bringing it into the cell, within a vesicle

(vacuole).

It’s a vacuole if

it just stores the

substance

Cells that store large quantities of

chemicals to be released do so in structures

called ____________.

1. snares

2. docking sacs

3. fusion sacs

4. vesicles

snare

s

dockin

g sacs

fusio

n sacs

vesicle

s

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i. Phagocytosis-

bringing in solids-like

food and cells.

http://www.colorado.edu/intphys/Class/IPHY3430-200/003membrane.htm

ii. Pinocytosis-

bringing in liquids.

Inner Surface of Plasma Membrane

Yellow arrow: Clathrin-coated pits

White arrow: Clathrin-coated

vesicle

Small micrograph: Caveolae

Endocytosis of LDL

http://www.susanahalpine.com/anim/Life/endo.h

tm

Endocytosis and Exocytosis

http://highered.mcgraw-

hill.com/sites/0072437316/student_view0/chap

ter6/animations.html

b. Exocytosis - opposite of endocytosis

i. Expels contents of vesicles out of the cell

ii. This is a way to rid the cell of wastes.

iii. Restores the membrane, so the cell doesn’t

shrink.

The process illustrated in Figure 7.01 is

called:

1. facilitated diffusion.

2. pinocytosis.

3. lysis.

4. exocytosis.

facil

itate

d diff

usion.

pinocy

tosis

.ly

sis.

exocy

tosis

.

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20Answer Now

A human white blood cell engulfs a

bacterial cell by:

1. carrier-mediated

facilitated diffusion.

2. exocytosis.

3. phagocytosis.

4. pinocytosis.

carri

er-media

ted fa

cilita

...

exocy

tosis

.

phagocyto

sis.

pinocy

tosis

.

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20Answer Now

c. Transcytosis – moving substances into,

across, and then out of a cell

d. Vesicular trafficking – moving substances

from one area in the cell to another

Which of the following is NOT an example

of simple diffusion?

1. gas exchange in our lungs

2. a dissolving sugar cube

3. popcorn odor permeating

the room

4. a white blood cell engulfing

a bacterium

gas ex

chan

ge in

our

lung

s

a dissolving

sug

ar cub

e

popc

orn od

or permea

tin...

a white

blood

cell e

ngulfi..

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Answer Now 20

In areas of the body exposed to the external

environment, such as the lungs, you would

expect which type of vesicular transport to

be most prevalent?

1. exocytosis

2. pinocytosis

3. phagocytosis

4. receptor-mediated

endocytosisexo

cyto

sis

pinocy

tosis

phagocyto

sis

rece

ptor-m

ediate

d end...

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Answer Now 20

e. Draw and label Endocytosis, Transcytosis and

Exocytosis

A bottle of perfume is opened on the

opposite side of the room and within

minutes you begin to smell the perfume.

This phenomenon is a classic example of:

1. facilitated diffusion.

2. osmosis.

3. active transport.

4. simple diffusion.

facil

itate

d diff

usion.

osmosis

.

activ

e tran

sport.

simple

diff

usion.

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20Answer Now

The movement of materials in a cell against

a concentration difference (from low to

high concentration) is called

1. facilitated diffusion.

2. active transport.

3. osmosis.

4. diffusion.

facil

itate

d diff

usion.

activ

e tran

sport.

osmosis

.

diffusio

n.

0% 0%0%0%

20Answer Now