Cells Part IIMembrane TransportMembrane Transport TermsMembrane Transport Passive Transport: DiffusionTypes of Diffusion Simple DiffusionTypes of Diffusion Facilitated DiffusionTypes of Diffusion OsmosisWhat are the end possibilities of Osmosis?Membrane Transport Passive Transport - FiltrationMembrane Transport Active TransportMembrane Transport Active Transport – Vesicular TransportVesicular Transport ExocytosisVesicular Transport EndocytosisCell DivisionCell Division Mitosis: Two daughter nuclei with exact same DNA as mother nucleusMitosis - MetaphaseMitosis - AnaphaseMitosis – Telophase and CytokinesisThe EndCells Part IICells Part IIReview solutions, solvents, and Review solutions, solvents, and solutes!solutes!Water is body’s main solventWater is body’s main solventSolutes are in smaller amounts, so Solutes are in smaller amounts, so tiny don’t settle out.tiny don’t settle out.Intracellular fluid – nucleoplasm and Intracellular fluid – nucleoplasm and cytosol, sol’n containing gases (O2, cytosol, sol’n containing gases (O2, CO2), nutrients, salts dissolved in water.CO2), nutrients, salts dissolved in water.Interstitial fluid – fluid bathes exterior of Interstitial fluid – fluid bathes exterior of cells, nutrients (aa, sugars, fatty acids, cells, nutrients (aa, sugars, fatty acids, vitamins), hormones, neurotransmitters, vitamins), hormones, neurotransmitters, salts, waste. Cells takes what it needssalts, waste. Cells takes what it needsSelective permeability – some things my Selective permeability – some things my pass through, things kept in and out of pass through, things kept in and out of cellcellPassive Transport – substances move Passive Transport – substances move across membrane w/o energy input from across membrane w/o energy input from cellcellDiffusion – movement of molecule from Diffusion – movement of molecule from high concentration to low concentrationhigh concentration to low concentrationThink of crowded elevator or classroomThink of crowded elevator or classroomSaves cells energySaves cells energyPM is barrier – What can pass?PM is barrier – What can pass?Small enough to pass through poresSmall enough to pass through poresDissolve in fatty portion of PM (nonpolar)Dissolve in fatty portion of PM (nonpolar)Assisted by membrane carrierAssisted by membrane carrierSimple diffusion – Simple diffusion – unassisted unassisted diffusion of diffusion of solutes through solutes through membranemembraneLipid-soluble – Lipid-soluble – fats, fat-soluble fats, fat-soluble vitamins, Ovitamins, O22, CO, CO22Figure 3.10aFacilitated Diffusion – lipid-Facilitated Diffusion – lipid-insoluble and too large to pass insoluble and too large to pass membranemembraneFollows laws of diffusionFollows laws of diffusionProtein ChannelProtein ChannelSmall enough to pass through pores – Small enough to pass through pores – some ions Clsome ions Cl--, Na+, K+, Na+, K+Protein ChannelProtein Channel Carrier-mediated Carrier-mediated Carrier molecule transport acrossCarrier molecule transport acrossSpecific to targetSpecific to targetChange in shape of carrier proteinChange in shape of carrier proteinFigure 3.10bFigure 3.10cCarrier-mediatedOsmosis – diffusion of Osmosis – diffusion of HH22O across membraneO across membraneHH22O polar, repelled by O polar, repelled by PM, used aquaporins PM, used aquaporins (proteins in membrane)(proteins in membrane)Occurs constantlyOccurs constantlyGlucose and OGlucose and O22 move move into cells – WHY?into cells – WHY?COCO22 and waste moving and waste moving out – WHY?out – WHY?Figure 3.10dIsotonic sol’nIsotonic sol’nEqual [solutes] inside cell Equal [solutes] inside cell and outside celland outside cellNo NET movement of waterNo NET movement of waterHypertonic sol’nHypertonic sol’nHigher [solutes] outside cell Higher [solutes] outside cell than insidethan insideNET movement of water out NET movement of water out of cellof cellCrenationCrenationHypotonic sol’nHypotonic sol’nHigher [solutes] inside cell Higher [solutes] inside cell NET movement of water NET movement of water into cellinto cellSwell and possible lyseSwell and possible lyseWater and solutes FORCED Water and solutes FORCED through PM through PM Passive process, but gradient Passive process, but gradient is pressure gradient (higher is pressure gradient (higher pressure to lower pressure)pressure to lower pressure)Not selectiveNot selectiveUsually occurs in capillaries Usually occurs in capillaries – – Kidney filtration, Intersitial Kidney filtration, Intersitial fluid, CSFfluid, CSFWhere is pressure higher – Where is pressure higher – arteriole or venule side of arteriole or venule side of capillary bed?capillary bed?What generates pressure?What generates pressure?Uses ATPUses ATPSolute pumps – Solute pumps – transport aa, some transport aa, some sugars, most ionssugars, most ionsAGAINST GRADIENTAGAINST GRADIENTTransports specific Transports specific substance, way for cell substance, way for cell to be selectiveto be selectiveSodium-potassium Sodium-potassium pump – transmission of pump – transmission of nerve impulsesnerve impulsesFigure 3.11Some substance can’t get across Some substance can’t get across PM via passive or active transportPM via passive or active transportUses ATPUses ATPMoves substance across w/o Moves substance across w/o passing through PMpassing through PMMoves substance out of cellMoves substance out of cellHow cells secretes hormones, mucus, other How cells secretes hormones, mucus, other products or wasteproducts or wastePackaged by Golgi in vesiclesPackaged by Golgi in vesiclesMigrates to PM and fusesMigrates to PM and fusesFigure 3.12ExocytosisUses ATPUses ATPTakes in or engulfs Takes in or engulfs extracellular substancesextracellular substancesMoves to cytoplasm Moves to cytoplasm binds to lysosomebinds to lysosomePinocytosis – imp. in cells Pinocytosis – imp. in cells of absorption, but all cellsof absorption, but all cellsPhagocytosis – phagocytic Phagocytosis – phagocytic cellscellsReceptor-mediated Receptor-mediated endocytosis – very selective endocytosis – very selective – enzymes, some hormones, – enzymes, some hormones, cholesterolcholesterolFigure