cells unit notes

1 CellsUnitNotes Name:

NEWAREAOFFOCUS:CELLULARBIOLOGYl FormFollowsFunction:Partsofthecellareshapedtoperformaparticularjob.

l Cellsarethestructuralandfunctionalunitsofalllivingorganisms

l Humanshave50-75Trillion–Multicellularl SomeProtistahave1–Unicellular

l ModernCellTheory

l -Thecellisbasicunitofstructureandfunctionl -Livingthingsaremadeofcellsl -Allcellscomefrompre-existingcells.l -Cellscontaingeneticinformationl -Allcellsaresimilarincompositionl -Energyflowoflifeoccursincells

l Therearetwotypesofcells.

l Prokaryoticl Eukaryotic

l Prokaryoticcells

l -Nonuclearmembranel -Geneticmaterialsisfreeincytoplasml -Nomembrane-boundorganellesl -Mostprimitivetypeofcell(appearedabout3.8billionyearsago)

l EukaryoticCellsl -Nuclearmembranesurroundinggeneticmateriall -Numerousmembrane-boundorganellesl -Appearedapproximatelyonebillionyearsagol -Complexinternalstructure

2 ORGANELLESINACELLAidforCellCityProject

Protoplasm–AllcontentsofthecellCytoplasm

n Allareasoutsideofnucleus.n Areaoutsideoforganellesiscalledcytosol.n Richchemicalfluidthathelpsbreakdownmoleculesforuse.

n Movesmaterialsthroughcell(foodandwaste)

CELLWALL

3 n Foundinplantsandbacterian Madeofcellulose(permeable)n Supportsplant

PlasmaMembrane

l -Madeofaphosolipidbilayer

l Phospholipidshavetwoends,oneofwhichishydrophilic,orattractedtowater,andoneofwhichishydrophobic,orrepelledbywater.

l -Thecellmembraneisselectivelypermeable.Somethingscanentersomecan’t.l -CellMembranecontrolsmovement(cellulartraffic)inandoutthecell.

Passivetransport-movementofmoleculesfromamorecrowdedtoalesscrowdedareaWITHOUTtheuseofenergy.Diffusion:Randommovementofmolecules.

l Fromhightolowconcentrationsl Moleculesaretryingtoreachequilibrium.

Osmosis:themovementofwaterthroughasemi-permeablemembrane.

l Permeable:Haslargeholesinittoletmoleculespassthrough.l Semi-permeable–Somethingscanenterl Impermeable–Nothingcanenter

l HypotonicSolution:Thecellhasahigherconcentrationinitthanintheareasurroundingit.

l Watermovesintothecelltoequaloutconcentration.Thecellswellsl HypertonicSolution:Concentrationofthecellislessthanoutsideofthecell.

l Watermovesoutofthecelltotrytoevenouttheconcentration.CellShrinks(Plasmolysis)l IsotonicSolution:Thecellhasaequalproportionofconcentrationwiththeareasurrounding.

l Watercontinuallyflowsinandouttokeepconcentrationeven.l Activetransport–

l -Movementofmoleculesfromalesscrowdedtoamorecrowdedareal -Requirestheuseofenergyl -Proteinscandothisl -Alsocalledreverseosmosis

n Endocytosis:(Endo-meanstobringin)Energyrequiringprocesswherecellengulfsparticle.

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l Phagocytosis:Typeofendocytosis.Membranesurroundslargeparticles(solids)l Pinocytosis:Membranesurroundsaliquidn TransmembraneProteinReceptorMediatedEndocytosis:Proteinsreceptorsfacilitateendocytosis.n Exocytosis:(Exo-meanstotakeout)Cellreleasesparticle.Usesenergy.

n

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TheNucleus

6 l -Largestorganelleincell(darkspot)l -Containsgeneticinformation(DNA)l -DNAmakesRNAwhichmakesproteinsl -Proteinsareimportantforcell.

Chromatin/Chromosomes •Containsgeneticinformation

•ComposedofDNA •Thickenintochromosomeswhencelldivides

•Setnumberperspecies(i.e.23pairsforhuman)Nucleolus •Rounddarkspotincenterofnucleus •Onlyvisiblewhencellisnotdividing •ContainsRNAforproteinmanufacturing

•Makesribosomesthattraveloutofnucleus.NuclearMembrane •SurroundsNucleus •Madeoftwolayers •Letsthingsinandout

RoughEndoplasmicreticulum(E.R.forshort)l -Maze-likenetworkfusedtonuclearmembrane.l -Goesfromnucleustocellmembrane.l -Stores,separates,andservesascell'stransportsysteml -Ribosomesattachtoandmakeproteins.l

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RoughE.R. SmoothE.R.SmoothE.R.

l -Makeslipids(fats)andsteriods.l -RegulatesCalciumproduction.l -Synthesizessugars“Gluconeogenesis”l -Detoxifiesdrugsl -Storesimportantenzymes

Ribosomes

l -Eachcellcontainsthousandsl -AminoAcids:Thebuildingblocksofproteins.20variationsl -Composes25%ofcell'smassl -Mostareembeddedinroughendoplasmicreticulum.Somefreeincytoplasm.l -SiteofProteinSynthesisl -Miniproteinmakingfactoriesl -Proteins(ONCH)areveryimportanttoourcellsandbody.l -DNAmakesRNA,RNAhasinformationtomakeproteins.l -RibosomesandmRNA

l

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ProteinSynthesis:TheprocessinwhichthegeneticcodecarriedbymessengerRNAdirectscellularorganellescalledribosomestoproduceproteinsfromaminoacids.ProteinsSynthesisAnimation

l Tomakeproteinsl RibosomesareunitsthathelpreadRNAl RNAistheinformationcodethattellsthetypeofproteinstobemade.l Proteinsynthesisistheprocessofmaking

GolgiApparatus

l Proteinpackagingplantandothermacromolecules.l Sendsvesiclesofmacromoleculestodestinationincell.l Composedofnumerouslayersformingasac.l Enzymesandcontentsoflysosomesaremadehere.

Lysosomesl HasDigestiveacids/enzymesinasacl Digestiveorganelle,recyclesoldcellparts.l Breaksdownproteins,lipids,andcarbohydrates,andbacteria.l Transportsundigestedmaterialtocellmembraneforremoval.l Cellbreaksdowniflysosomeexplodes

Cytoskeleton,microtubules,microfilaments

l Composedofmicrotubulesl Supportscellandprovidesshapel Aidsmovementofmaterialsinandoutofcellsl Flagellumismadeofmicrotubules

Centrioles

l Looklikegoldennuggets(Paired)l Madeofninetubesl Aidincelldivision(Mitosis)

Plastids(AKAChloroplast)

l Organelleinplantsl Containthegreenpigmentchlorophylll HasstackscalledThylakoidsl Dophotosynthesis(Makethesugar)l Hasit’sownuniqueDNA.

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l Photosynthesis–Plantsmakesugarfromsunlight.Lightenergyisturnedintochemicalenergy(sugars–carbonbased).6CO2+6H2O+lightenergy=C6H12O6+6O2

Photosynthesis

l Producessugarsfromenergy.l Occursonlyincellswithchloroplasts.l Oxygenisproduced.l Waterisused.l Carbondioxideisused.l Occursinlight.

Mitochondria

l Largeorganellethatmakesenergyforthecell.(ATP)l Hasfolds(surfacearea)calledcristael Twomembranesl Recycleswastes,producesureal HasitsownDNA.Reproduceindependentlyfromcell.

CellularRespiration:Processeswherebycertainorganismsobtainenergyfromorganicmolecules.CellularRespiration

l C6H12O6+6O2=6CO2+6H2O+releasedenergy.Respiration

l Burnssugarsforenergy.l Energyisreleased.l Occursinmostcells.

10 l Oxygenisused.l Waterisproduced.l Carbondioxideproduced.l Occursindarkandlight.

Thecarbondioxideoxygenbalance.

l Plantusescarbondioxideandproducesoxygen(photosynthesis).l Animalusesoxygenandproducescarbondioxide(respiration).

l Vacuoles

l Membrane-boundsacsforstorage,digestion,andwasteremovall Verylargeinplantcelll Createturgidpressureinplantsl Containsfoodandwatersolutionl Contractilevacuolesforwaterremoval(inunicellularorganisms)+locomotion.

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SAVETHESENOTESFORTHEASSESSMENTWHICHISDUESHORTLY!