Transporting Molecules CELL MEMBRANE also called plasma membrane

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) PERIPHERAL Proteins that stick INTO membrane = INTEGRAL (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/U 3 Cell/diffusion_1. png

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 DIFFERENCE • Happens anytime there is a _____ in concentration in one place compared to another = Concentration gradient (____________)

DIFFUSION across a space • Molecules move automatically from an area of _______ Higher concentration to an area of ____ Lower 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/import. Prot. 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_05 oxygen. gif

What if cell needs to move large or polar molecules? EX: Glucose Amino acids

What if cell needs to move a molecule AGAINST the CONCENTRATION GRADIENT? (LOW HIGH) Example : Glucose into mitochondria 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 + + _______ Na & K ions sends nerve signals http: //www. steve. gb. com/images/science/neuron. png

2 KINDS of TRANSPORT across cell membranes PASSIVE • ______TRANSPORT Does NOT require energy • ______TRANSPORT ACTIVE Requires energy

Kidspiration by: Riedell

Kinds of Passive Transport • _________________ Diffusion • Osmosis • __________________ Facilitated Diffusion • Ion Channels ___________________________________

DIFFUSION across a membrane DIFFERENCE • 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: OXYGEN ______________ CARBON DIOXIDE http: //www. lionden. com/cell_animations. htm

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

DIFFUSION or OSMOSIS HIGHER LOWER DIFFUSION 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

Osmosis 1 http: //www. sidwell. edu/us/science/vlb 6/labs/a_osmosis. gif

Kinds of Passive Transport • _________________ Diffusion • Osmosis • __________________ Facilitated Diffusion • Ion Channels ___________________________________

Facilitated Diffusion Carrier proteins help diffusion go faster

FACILITATED DIFFUSION NO energy required • Passive = __________ HIGH LOW • Moves from ____________ Carrier Proteins bind molecule, change • ___________ shape, and release it on other side of membrane Integral (Carrier proteins are ________ proteins) • Molecules that move this way in cells: GLUCOSE ____________

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 PASSIVE • _______transport (no energy required) HIGH LOW • Molecules move from __________ • Small passageways for _______ IONS 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: //www 2. uic. edu/~myilma 1/ionchannel. gif

Kidspiration by: Riedell

Kinds of Active Transport • ____________________ Sodium-Potassium Pump • Endocytosis __________________ • __________________ Exocytosis

SODIUM-POTASSIUM PUMP ATP • ______ ACTIVE transport (requires energy from ______) • Special just for Na+ and K + ions Carrier Proteins to move molecules • Uses integral __________ • Examples in nerve cells: Na+ is pumped out of cells at same time K + is taken into cells

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

ENDOCYTOSIS Takes substances into cell • _______transport (requires energy from ATP) ACTIVE • Uses small membrane sacs to carry substances = VESICLES _______ http: //www. sirinet. net/~jgjohnso/cell. html

2 KINDS of ENDOCYTOSIS Takes substances into cell If taking in: PINOCYTOSIS fluid, molecules = __________ PHAGOCYTOSIS 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/bio 4 fv/page/cell-movement. html

PHAGOCYTOSIS White blood cell destroying germs

EXOCYTOSIS Substances released outside of cell ACTIVE transport (requires energy) • _____ VESICLES • Substances move in______ • Examples in cells: – Golgi release packaged proteins

Exocytosis http: //www. emc. maricopa. edu/faculty/farabee/BIOBK/Bio. Booktransp. html

GOLGI BODIES USE EXOCYTOSIS Animation from: http: //www. franklincollege. edu/bioweb/A&Pfiles/week 04. html

Endocytosis & Exocytosis http: //grossmont. gcccd. cc. ca. us/cmilgrim/Bio 120/Outline/ Outline 2. gif/Transport. Media/Endo. Exocytosis. Movie. htm