WELCOMETOHumanPhysiology(LECTURESESSION)Department of PhysiologyYangzhou University School of MedicineSpring2020
WELCOME TO Human Physiology (LECTURE SESSION) Department of Physiology Yangzhou University School of Medicine Spring 2020
Chapter2BasicFunctionsofCells-Membrane Structureand MembraneTransport-SignalTransduction--MembranePotential--MuscleCell Contraction
Chapter 2 Basic Functions of Cells - Membrane Structure and Membrane Transport - Signal Transduction - Membrane Potential - Muscle Cell Contraction
CellMembraneStructure55%Proteins25%Phospholipids13%Cholesterol4%Otherlipids3%CarbohydratescarbohydrateEndoplasmicchainretcuumcholesterolFreeribosotRiboscmeMaochondria(dots)CalNuheulphospholipidmembranebilayerProteinmoleculeglycoproteinhydrophilichydrophobicregonsregion
Cell Membrane Structure Proteins 55% Phospholipids 25% Cholesterol 13% Other lipids 4% Carbohydrates 3%
CrossCellMembraneTransport1.SimpleDiffusionCarrierFacilitated Diffusion(noATPneeded)Channel2.Protein-mediatedPrimaryActive Transport(ATPdependent)Secondary3.Vesicle-mediated:Endocytosis/ExocytosisFacilitateddiffusionActiveSimpleChannelCarrierFoodparticleEnvironmentTransporterDiffusionTransporterTransportertakeninbyendocytosisNatGlucoseNaOExocytosisofwasteFoodProductsofparticlesCdigesteddigestionFusionformssecondaryATPK+ADP+PNat2GlucoselysosomeNaPassiveActive
Cross Cell Membrane Transport 1. Simple Diffusion 2. Protein-mediated Facilitated Diffusion (no ATP needed) Active Transport (ATP dependent) Carrier Channel Primary Secondary 3. Vesicle-mediated: Endocytosis/Exocytosis Passive Active Facilitated diffusion
OsmosisIsotonic:Solute concentrationsare equal inside and out.CellsmaintainPlaceinhypotonicnormalOsmosissolution.shape.-SemipermbeableOsmosisisthemovementofwater(reddots)throughasemipermeablemembranemcmbranetoahigherconcentration ofsolutes(blueHypotonicsolution:dots).SoluteconcentrationPlace inis lower outside thehypertonicWater easily moves through cellcell.solution.membranesbyosmosis.HighLowSoluteSoluteCellsswell andHypertonic solution:may even ruptureSolute concentrationbecause waterisis higher outside thetaken into the cell.cell.Cellsshrinkbecausewater exitsthe cell
Osmosis