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CellsCELLULAR COMPONENTS

& PROCESES

ModernCellTheory

1.  Alllivingorganismsarecomposedofoneormorecells.

2.  Thecellisthebasicunitofstructureandorganizationinorganisms.

3.  Cellsarisefrompre-existingcells.

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ExceptionstotheCellTheoryVIRUSES

Viruseslacktheabilitytogenerateenergyontheirown,andalsogeneratenowasteproducts,bothhallmarksoflivingorganisms.Virusesalsolacktheabilitytoreplicatewithoutfirstinvadingahostcell.

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ExceptionstotheCellTheoryMITOCHONDRIAand

CHLOROPLASTS

BothareorganelleswithinacellthatcontaintheirownDNAandcanreplicatewithinacellwithoutthecellactuallydividing.

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1.  Prokaryotic-cellsthatDONOThaveanucleusThegeneticmaterialisfoundinthecytoplasm.Inaddition,thereareonlyafewcellORGANELLES

2.  Eukaryotic-cellswithaNUCLEUSandcellORGANELLES.Geneticmaterialisfoundinthenucleus

TwoTypesofCells

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* Little“organs”ofthecell* Workforcellslikeorgansworkformorecomplexorganisms.* OrganellesarepresentinBOTHplantsandanimals* Carryoutcellularfunctions!

Organelles

* ThepartsofacellthatcarryoutafunctionarecalledcellORGANELLES:(Mini-Organs)* Allcellshavethefollowingorganelles:* CellMembrane* Cytoplasm* Ribosomes* Cytoskeleton

Organelles

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*  Nucleus*  Nucleolus*  Mitochondria*  GolgiBodyComplex*  EndoplasmicReticulum*  Vacuole*  Lysosome*  Centrioles(ANIMALONLY)PlantCellshavealloftheaboveand:*  CellWall*  Chloroplast

EukaryotesAlsoHave…

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* Cellularcontrolcenter* Controlscellularactivity* Containsgeneticmaterial(TightlycoiledDNAcalledchromosomes)* Selfduplicatingstructure-divideswhenthecelldivides

Nucleus

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* Roundorganelleinsidethenucleus* Involvedwiththesynthesisofribosomes

Nucleolus

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* Surroundsnucleusallowingcertainmaterialstoenterandleave.* AKAthenuclearenvelope

NuclearMembrane

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* Siteofproteinsynthesisinthecytoplasm* Maybefreefloatinginthecytoplasmorattachedtotheendoplasmicreticulum

Ribosomes

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* Cytoplasmicchannels(pathways)fromthenuclearmembranetothecellmembrane* Associatedwiththestorage,synthesis,andtransportofmaterialswithinthecell

EndoplasmicReticulum(ER)

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* Jelly-likematerialbetweenthecellmembraneandthenucleus* Over80%water* “HOLDS”cellorganellesinplace* Citeofmostorganellesandcellularchemicalreactions

Cytoplasm

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* Asmallcavityinthecytoplasmofacell,boundbyasinglemembraneandcontainingwater,food,ormetabolicwaste.* **Vacuolesarecrucialinsingle-celledorganismsTwoTypes:* Foodvacuole-store&digestingestedfood* Contractilevacuole-pumpsexcesswaterfromcellsmaintaininghomeostasis

Vacuole

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* Alargecavityfoundinplantcellsprimarilyforwaterstorage

CentralVacuole

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* Pouchcontainingdigestiveenzymes* Digestbacteriaandsomefoodsenteringthecell* Breaksdowncomplexmoleculesintosimplermolecules* Breakdownwornoutcellorganelles

Lysosome

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* "Powerhouseofthecell"* Carriesoncellularrespiration(containsrespiratoryenzymesthatmakeATP-energymolecule)* ContainsDNA--isselfduplicating--divideswhenthecelldivides* Foundingreater#sinactivecells

Mitochondria

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* Usuallylocatednearthenucleus* Synthesizes,packages,andsecretescellularproducts* Packageswaste&harmfulmaterials

GolgiApparatus(Complex)

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* ThecellmembraneisSEMI-PERMEABLE*  selectivelyregulatestheflowofmaterialstoandfromthecell--thusmaintainingchemicalhomeostasiswithinthecell* ThemembraneactslikeaBOUNCERonlyallowingcertainthingsinandoutofthecell*  Itismadeupofalipidbilayer* doublelayerofFAT-"Fatsandwich"*  transportthroughtheplasmamembranelikelyoccursthroughtheseglobularproteins(Fluidmosaicmodel)

Plasma(CELL)Membrane

* Hydrophilic-attractswater* Hydrophobic-repelswater* Whyisitimportantthatthecellmembraneismadeupofsmallphospholipids?

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* Centriole-acylindricalstructurefoundinthecytoplasmwhichappearstofunctionduringthedivisionofcertainanimalcells(usuallynearthenucleus)* Helpsanimalcellsdivide

OrganellesFoundONLYinAnimals

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* CellWall-anonlivingstructurewhichsurroundsandsupportsthecell-composedmostlyofcellulose*  Givestheplantcellstructure&support* Chloroplasts-greenincolor-doublemembrane-containthegreenpigmentchlorophyllwhichcarriesonphotosynthesis*  Has DNA & is self replicating like the

mitochondrion

OrganellesfoundONLYinPlants

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