Transporting Molecules

CELL MEMBRANE (also called plasma membrane) Cell membranes are made of ________________ & __________________ PHOSPHOLIPIDS PROTEINS

CELL MEMBRANE Proteins that stick on the surface = _____________ (either inside or outside of cell) Proteins that stick INTO membrane = ________________ (can go part way in or all the way through)

GLYCOPROTEINS Recognize “self” GLYCOPROTEINS are INTEGRAL PROTEINS

SELECTIVELY PERMEABLE (semi-permeable)

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

from “where there’s A LOT” to “where there’s NOT” Animatioin from: http://www.biologycorner.com/resources/diffusion-animated.gif Molecules move from “where there’s A LOT” to “where there’s NOT”

DIFFUSION across a space Happens anytime there is a __________ in concentration in one place compared to another (________________________)

DIFFUSION across a space Molecules move automatically from an area of _______ concentration to an area of ________ concentration EX: _____________________ _____________________ Perfume, Koolaid, popcorn, BBQ, Bad smell in room http://leighhouse.typepad.com/blog/images/kool_aid.jpg http://www.swapmeetdave.com/Humor/Farts.htm

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

Gas exchange between lungs and blood happens by DIFFUSION from HIGHER concentration to LOWER concentration Image modified from: http://www.medaille.edu/vmacer/120_graphic_05oxygen.gif

What if cell needs to move large or polar molecules? EX: _______________

What if cell needs to move a molecule AGAINST the CONCENTRATION GRADIENT? (LOW  HIGH) Example : _______________________ Image from: http://www.biologyclass.net/mitochondria.jpg

What if cell needs to move molecules really FAST 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

2 KINDS of TRANSPORT across cell membranes Does NOT require energy ___________TRANSPORT Requires energy

Kidspiration by: Riedell

Kinds of Passive Transport __________________________________ ___________________________________

DIFFUSION across a membrane Happens anytime there is a __________ in concentration on one side of the membrane compared to the other Molecules that move by diffusion across membranes in cells: ______________ http://www.lionden.com/cell_animations.htm

OSMOSIS = SPECIAL KIND OF DIFFUSION MOVES WATER MOLECULES Across a MEMBRANE From HIGHER  LOWER http://www.Isbu.ac.uk/water/molecule.html

DIFFUSION or OSMOSIS HIGHER  LOWER Can happen with or without a membrane Molecules that do it: All molecules EXCEPT water Goes until equilibrium Example in cells: Oxygen & Carbon dioxide OSMOSIS Happens 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 concentration reaches equilibrium

 Osmosis1 http://www.sidwell.edu/us/science/vlb6/labs/a_osmosis.gif

Kinds of Passive Transport __________________________________ ___________________________________ Diffusion Osmosis Facilitated Diffusion Ion Channels

Facilitated Diffusion Carrier 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: _______________________

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 +

ION CHANNELS Some channels always open Some channels have “gates” that open or close in response to signals SIGNALS: stretching of cell membrane electrical signals chemicals Animation from: http://www2.uic.edu/~myilma1/ionchannel.gif

Kidspiration by: Riedell

Kinds of Active Transport ________________________________________ ___________________________________ ____________________________________

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

Na+ and K + PUMP Animation from: http://www.lionden.com/cell_animations.htm

ENDOCYTOSIS Takes substances into cell _____________transport (requires energy from ATP) Uses small membrane sacs to carry substances ______________ http://www.sirinet.net/~jgjohnso/cell.html

2 KINDS of ENDOCYTOSIS Takes 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

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

PHAGOCYTOSIS White blood cell destroying germs

EXOCYTOSIS Substances released outside of cell __________ transport (requires energy) Substances move in____________ Examples in cells: Golgi release packaged proteins

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