CELLULAR TRANSPORTCELLULAR TRANSPORT((Movement of materials across a cellular Movement of materials across a cellular

membrane)membrane)

Chapter 8, Section 1Chapter 8, Section 1

DiffusionDiffusion = movement of molecules from = movement of molecules from an area of an area of high concentrationhigh concentration to an area of to an area of low concentrationlow concentration Ex. Food in the kitchen, perfume/cologne in a Ex. Food in the kitchen, perfume/cologne in a

classroom.classroom. Molecules are constantly moving around, Molecules are constantly moving around,

sometimes fast sometimes slowsometimes fast sometimes slow http://highered.mcgraw-hill.com/sites/00724958

55/student_view0/chapter2/animation__how_diffusion_works.html

Osmosis

OsmosisOsmosis = diffusion of = diffusion of WATERWATER across a across a membrane, membrane, your cells are mostly water!!!your cells are mostly water!!!

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

Direction of Osmosis (p.196)Direction of Osmosis (p.196)

SoluteSolute = substance that = substance that getsgets dissolved dissolved SolventSolvent = substance = substance doesdoes the dissolving the dissolving HypotonicHypotonic = concentration of solutes outside of = concentration of solutes outside of

cell is cell is lower lower than concentration of solutes in than concentration of solutes in cytosol, water moves into cellcytosol, water moves into cell

HypertonicHypertonic = conc. of solutes outside of cell is = conc. of solutes outside of cell is higherhigher than conc. of solutes in cytosol, water than conc. of solutes in cytosol, water moves out of cellmoves out of cell

IsotonicIsotonic = conc. of solutes inside & outside cell = conc. of solutes inside & outside cell are equal, water moves in & out at equal ratesare equal, water moves in & out at equal rates

Large black dots are solute – compare amount inside vs. outsideLarge black dots are solute – compare amount inside vs. outsideGoogle – Glencoe Osmosis Virtual LabGoogle – Glencoe Osmosis Virtual Lab

Practice with Osmosis:Practice with Osmosis: Where is there more Where is there more

water?water?

Which way is the Which way is the water going to water going to move?move?

What type of What type of solution is this?solution is this?

Hold your Wee for a WiiHold your Wee for a Wii

In 2007 a woman died participating in a In 2007 a woman died participating in a California radio station contest to win a video California radio station contest to win a video game console. The coroner’s report game console. The coroner’s report indicated she died of water intoxication, indicated she died of water intoxication, hyponatremia. During the contest, hyponatremia. During the contest, participants were given two minutes to drink participants were given two minutes to drink a bottle of water and then given another a bottle of water and then given another bottle to drink after a 10 minute break. This bottle to drink after a 10 minute break. This was repeated several times. Explain what was repeated several times. Explain what you think was happening to the woman’s you think was happening to the woman’s body and her cells.body and her cells.

Overconsumption of WaterHyponatremia

Human body has approximately 1.25 gallons of blood.

Too much water too little sodium causes imbalance.

Damage to heart occurs – Why? Damage to kidneys occurs – Why? Systems shut down and coma/death can result. Cure – attempt to rebalance sodium and water. Marathon runners have died due to this condition.

Passive Transport (p.198)Passive Transport (p.198)

Cell does Cell does NOTNOT useuse energy to move energy to move particles across the particles across the plasma membraneplasma membrane

Facilitated DiffusionFacilitated Diffusion = passive transport of = passive transport of materials using materials using proteinsproteins

Active Transport (p. 199)Active Transport (p. 199) Cell requires energy (from mitochondria) Cell requires energy (from mitochondria)

to move particles from to move particles from low concentration low concentration to high concentrationto high concentration

Transport of Large Particles (p. 200)Transport of Large Particles (p. 200)

EndocytosisEndocytosis = cell = cell surround and surround and takes intakes in materials from its materials from its environmentenvironment

ExocytosisExocytosis = cells = cells release release materials materials from the inside out from the inside out into the environmentinto the environment

PracticePractice

How would you expect the amount of How would you expect the amount of mitochondria (energy producing mitochondria (energy producing structures) in a cell to be related to the structures) in a cell to be related to the amount of active transport it carries out? amount of active transport it carries out? Explain your answer.Explain your answer.