Cells Unit Notes
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1 Cells Unit Notes Name: NEW AREA OF FOCUS: CELLULAR BIOLOGY l Form Follows Function: Parts of the cell are shaped to perform a particular job. l Cells are the structural and functional units of all living organisms l Humans have 50-75 Trillion – Multicellular l Some Protista have 1 – Unicellular l Modern Cell Theory l -The cell is basic unit of structure and function l -Living things are made of cells l -All cells come from pre-existing cells. l -Cells contain genetic information l -All cells are similar in composition l -Energy flow of life occurs in cells l There are two types of cells. l Prokaryotic l Eukaryotic l Prokaryotic cells l - No nuclear membrane l - Genetic materials is free in cytoplasm l - No membrane-bound organelles l - Most primitive type of cell (appeared about 3.8 billion years ago) l Eukaryotic Cells l - Nuclear membrane surrounding genetic material l - Numerous membrane-bound organelles l - Appeared approximately one billion years ago l - Complex internal structure
Transcript of 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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