Transporting Molecules

CELL MEMBRANE(also called plasma membrane)

Cell membranes are made of ________________ & __________________ PHOSPHOLIPIDS PROTEINS

CELL MEMBRANE

Proteins that stick on the surface = PERIPHERAL(either inside or outside of cell)

Proteins that stick INTO membrane = INTEGRAL(can go part way in or all the way through)

Recognize “self”

GLYCOPROTEINS

GLYCOPROTEINS are INTEGRAL PROTEINS

SELECTIVELY PERMEABLE(semi-permeable)

Diffusion

http://lhs.lps.org/staff/sputnam/Biology/U3Cell/diffusion_1.png

Molecules move

from “where there’s A LOT”

to “where there’s NOT”

Animatioin from: http://www.biologycorner.com/resources/diffusion-animated.gif

DIFFUSION across a space

• Happens anytime there is a __________ in concentration in one place compared to another

(________________________)

DIFFERENCE

= Concentration gradient

DIFFUSION across a space

• Molecules move automatically from an area of _______ concentration to an area of ________ concentration

• EX: _____________________ _____________________

HigherLower

Perfume, Koolaid, popcorn,BBQ, Bad smell in room

http://www.swapmeetdave.com/Humor/Farts.htmhttp://leighhouse.typepad.com/blog/images/kool_aid.jpg

Molecules need to

move across membranes

in cells

Image modiified from: http://www.accessexcellence.org/AB/GG/importProt.html

Diffusion can happen across a membrane in a cell

…as long as membrane will let molecule through

SELECTIVELY PERMEABLE

happens by DIFFUSION from HIGHER concentration to LOWER concentration

Image modified from: http://www.medaille.edu/vmacer/120_graphic_05oxygen.gif

Gas exchange between lungs and blood

What if cell needs to move large or polar molecules?

EX:

GlucoseAmino acids

What if cell needs to move a molecule AGAINST the CONCENTRATION GRADIENT?

Example :

Glucose into mitochondria

(LOW HIGH)

Image from: http://www.biologyclass.net/mitochondria.jpg

What if cell needs to move molecules really FAST? (can’t wait for it to diffuse)

Example in cells:

Movement of ______________ions sends nerve signals

http://www.steve.gb.com/images/science/neuron.png

Na + & K+

2 KINDS of TRANSPORTacross cell membranes

• ____________TRANSPORT Does NOT require energy

•___________TRANSPORTRequires energy

PASSIVE

ACTIVE

Kidspiration by: Riedell

Kinds of Passive Transport

• Diffusion

•Osmosis•Facilitated Diffusion•Ion Channels

__________________________________

___________________________________

___________________________________

___________________________________

DIFFUSION across a membrane• Happens anytime there is a __________

in concentration on one side of the membrane compared to the other

DIFFERENCE

Molecules that move by diffusion across membranes in cells:____________________________

OXYGEN

CARBON DIOXIDEhttp://www.lionden.com/cell_animations.htm

OSMOSIS

• MOVES WATER MOLECULES

• Across a MEMBRANE

• From HIGHER LOWER

= SPECIAL KIND OF DIFFUSION

http://www.Isbu.ac.uk/water/molecule.html

DIFFUSION or OSMOSISHIGHER LOWER

DIFFUSIONCan happen with or without

a membrane

Molecules that do it: All molecules EXCEPT

water

Goes until equilibrium

Example in cells:Oxygen & Carbon dioxide

OSMOSISHappens across a

membrane

Molecules that do it:Water

Goes until equilibrium

Example in cells:Water

What if there is a difference in concentration but solute molecules

can’t move across a membrane?

WATER will move until concentrationreaches equilibrium

http://www.sidwell.edu/us/science/vlb6/labs/a_osmosis.gif

 Osmosis1

Kinds of Passive Transport

• Diffusion

•Osmosis•Facilitated Diffusion•Ion Channels

__________________________________

___________________________________

___________________________________

___________________________________

Facilitated DiffusionCarrier proteins help diffusion go faster

FACILITATED DIFFUSION• Passive = ____________________

• Moves from ________________________

• _____________________ bind molecule, change shape, and release it on other side of membrane

(Carrier proteins are _______________ proteins)

• Molecules that move this way in cells:_______________________

NO energy required

Carrier Proteins

Integral

GLUCOSE

HIGH LOW

Facilitated Diffusion

Animation from: http://bio.winona.edu/berg/ANIMTNS/facdifan.gif

Kinds of Passive Transport

• Diffusion

•Osmosis•Facilitated Diffusion•Ion Channels

__________________________________

___________________________________

___________________________________

___________________________________

ION CHANNEL

ION CHANNELS• _____________transport (no energy required)

• Molecules move from ___________________

• Small passageways for _______ to get through membrane

• Each ion has own kind of passageway

• Examples in cells: Na+ , Cl- , Ca + + , K +

PASSIVE

HIGH LOW

IONS

ION CHANNELS

Some channels always open

Some channels have “gates”

that open or close

in response to signals

Animation from: http://www2.uic.edu/~myilma1/ionchannel.gif

SIGNALS:•stretching of cell membrane•electrical signals•chemicals

Kidspiration by: Riedell

Kinds of Active Transport

• Sodium-Potassium Pump•Endocytosis

•Exocytosis

________________________________________

___________________________________

____________________________________

SODIUM-POTASSIUM PUMP

• ___________ transport (requires energy from ______)

• Special just for Na+ and K + ions

• Uses integral ___________________ to move molecules

• Examples in nerve cells: Na+ is pumped out of cells at same time K + is taken into cells

ACTIVE

Carrier Proteins

ATP

Na+ and K + PUMP

Animation from: http://www.lionden.com/cell_animations.htm

ENDOCYTOSISTakes substances into cell

• _____________transport (requires energy from ATP)

• Uses small membrane sacs to carry substances

______________

ACTIVE

= VESICLES

http://www.sirinet.net/~jgjohnso/cell.html

2 KINDS of ENDOCYTOSISTakes substances into cell

If taking in:

fluid, molecules = ____________________

large particles or whole cells = __________________

• Examples in cells:– one celled organisms eat this way– white blood cells get rid of bacteria this way

PINOCYTOSIS

PHAGOCYTOSIS

ENDOCYTOSIS

Animation from: http://academic.brooklyn.cuny.edu/biology/bio4fv/page/cell-movement.html

PHAGOCYTOSIS

White blood cell destroying germs

EXOCYTOSISSubstances released outside of cell

• __________ transport (requires energy)

• Substances move in____________

• Examples in cells:

– Golgi release packaged proteins

ACTIVE

VESICLES

Exocytosis

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBooktransp.html

GOLGI BODIES USE EXOCYTOSIS

Animation from: http://www.franklincollege.edu/bioweb/A&Pfiles/week04.html

Endocytosis & Exocytosis

http://grossmont.gcccd.cc.ca.us/cmilgrim/Bio120/Outline/Outline2.gif/TransportMedia/EndoExocytosisMovie.htm