Cell-Structure-and-Function

1CellTheoryandCellularStructures2CellHistory•Term“cell”wascoinedin1665byRobertHookewhenhelookedatasliceofdriedcork.•Hookewasabletoviewthecellswiththehelpofamicroscope–inventedbyAntonvanLeeuwenhoek•Inthe1830’s,MatthiasSchleidenobservedplantsandTheodorSchwannobservedanimalsunderamicroscopeanddiscoveredbotharecomposedofcellsIn1855,RudolphVirchowproposedthatallcellscomefromexistingcells3CellTheory•Withtheobservationsmadebythesescientists,thecelltheorywasdeveloped:3partsoftheCellTheory:1.)Allorganismsarecomposedofoneormorecells.2.)Cellsarethesmallestlivingunitsofalllivingorganisms.3.)Cellscomefrompreexistingcells4ExploringtheCell•Inthe1940’s,anewmicroscope,theelectronmicroscope,wasdevelopedtoseebeyondtherealmofthecell–2typesofelectronmicroscopes:TransmissionElectronMicroscope(TEM):beamsofelectronsarepassedthroughthinsamplesScanningElectronMicroscope(SEM):beamsofelectronsarescennedoverthesurfaceofaspecimen;3-Dimagesmade;specimensmustbeplacedinavacuum5ExploringtheCell•TEMimage:•SEMimage:6CellStructures•Withthehelpofthesemicroscopes,scientistsdiscoveredorganelles–Organelles:membraneboundstructureswithinacell7CellTypes•Twobroadgroupsofcells:•Prokaryotic:nomembraneboundorganellesex.bacteria–Eukaryotic:membraneboundorganellesex.Animalandplantcells8ProkaryoticCellsvsEukaryoticcells•PROKARYOTICCELLS:–Simplestorganisms;muchsmaller–Cytoplasmissurroundedbyplasmamembraneandencasedinarigidcellwall.–Nonucleus(DNAcontainedwithinaregioncalledtheNUCLEOID)–Nomembraneboundorganelles•EUKARYOTICCELLS:–Morecomplexorganisms–Hasanucleusandothermembraneboundorganelles(specializedstructureswithspecificfunctions)9GeneralizedEukaryoticCell10CellDiversity•Lotsofshapesandsizes11EUKARYOTICCELLS:•2MaintypesofEukaryoticcells–AnimalandPlantcells–4differencesbetweenthemPlantcells:cellwallchloroplastslargecentralvacuoleAnimalcells:centrioles12AnimalCell13PlantCell14CellularStructuresandFunctions•Nucleus:–controlsthecellwithDNAinformation–THEBRAINorTHEBOSS15Nucleus16Cytoplasm•Cytoplasm:gel-likematerialthatmakesuptheinsideofthecell•THEGEL17PlasmaMembrane•PlasmaMembrane:regulateswhatentersandleavesthecell•THEBOUNCER•Madeofalipidbilayer18EndomembraneSystem•Endoplasmicreticulum–Producesproteinsandlipidstobetransferredorexported–THETRANSPORTERRoughER-studdedwithribosomesSmoothER-fewribosomes19EndomembraneSystem•Golgiapparatus–Collect,package,anddistributemolecules(proteins)synthesizedatonelocationinthecellandutilizedatanotherlocation–MR.MAILMANorMr.UPS20LysosomesandVacuoles•Lysosomes-membrane-boundvesiclescontainingdigestiveenzymes–fromGolgi–MR.CLEAN–Cleananddigestoldcellparts•Vacuoles-storewater,proteins,carbohydrates,andsalt–THEKITCHENSINKorFRIDGE21Ribosomes•Ribosomes:siteofproteinsynthesis;whereaminoacidscometogethertomakeproteins•THEMAKER22OrganellesWithDNA•Mitochondria–Produceenergyfromthecellwithcellularrespiration–POWERHOUSE•Chloroplasts–Usesunlighttoproducechemicalenergyusingphotosynthesis–foundinphotosyntheticorganismsPlantcells–THEGREENMACHINE23Mitochondria24Chloroplasts25Cytoskeleton•Networkofproteinfiberssupportingcellshapeandanchoringorganelles;allowsmovement•THESKELETONActinMicrotubulesIntermediatefilaments26Cytoskeleton27PlantCells•Centralvacuole–oftenfoundinthecenterofaplant,andservesasastoragefacilityforwaterandothermaterials•Cellwall–providessupportandprotection–THEGREATWALL28PlantCell2930