L1 eukaryote prokaryote

8/3/2019 L1 eukaryote prokaryote

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SHES 1201: Cell BiologySHES 1201: Cell Biology

Lecture 1Lecture 1

Introduction toIntroduction toProkaryotic and Eukaryotic cellsProkaryotic and Eukaryotic cells


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ReferenceReference The World of the CellThe World of the Cell -- 66thth editionedition

Pearson Education Inc. 2006Pearson Education Inc. 2006

J.HardinJ.Hardin

BiologyBiology -- 77thth editionedition

Pearson Education Inc. 2005Pearson Education Inc. 2005Campbell and ReeceCampbell and Reece

READ! READ! READ!READ! READ! READ!


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CELLCELL

All living things are made of cellsAll living things are made of cells

CellCell basic unit of lifebasic unit of life

EukaryotesEukaryotes

ProkaryotesProkaryotes: bacteria: bacteria

EukaryotesEukaryotes: all other forms of life: all other forms of life


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PROKARYOTESPROKARYOTESBased on molecular andBased on molecular and

biochemical criteria:biochemical criteria:

EubacteriaEubacteria (true(truebacteria)bacteria)

ArchaeaArchaea Similar toSimilar to eubacteriaeubacteria

(cellular structure)(cellular structure) Molecular andMolecular and

os presen ayos presen aybacteria andbacteria andcyanobacteriacyanobacteria

biochemicalbiochemicalconstituents differentconstituents differentfromfrom eubacteriaeubacteria andandeukaryoteseukaryotes

EgEg.. MethanobacteriaMethanobacteria,,halobacteriahalobacteria,,sulfobacteriasulfobacteria,,thermacidophilesthermacidophiles


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EUKARYOTESEUKARYOTES

Simple eukaryotesSimple eukaryotes

Algae, protozoa, yeast, fungiAlgae, protozoa, yeast, fungi mp e an ma s : y ra, s ar s ,mp e an ma s : y ra, s ar s ,

jelly fish, coralsjelly fish, corals

MulticellularMulticellular eukaryoteseukaryotesAnimal cellsAnimal cells

Plant cellsPlant cells


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Differences betweenDifferences between

rokar otes and eukar otesrokar otes and eukar otes


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Membrane bounded nucleusMembrane bounded nucleus

ProkaryotesProkaryotes

No membraneNo membrane


True membraneTrue membrane boundedbounded

nucleusnucleus

nucleosidnucleosid ene c n orma on n eene c n orma on n e

nucleusnucleus

Nucleus has nucleolus,Nucleus has nucleolus,

site of ribosomesite of ribosomesynthesis, DNA bearingsynthesis, DNA bearingchromosomeschromosomes


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OrganellesOrganelles

ProkaryotesProkaryotes

Few internalFew internalmembranemembrane

EukaryotesEukaryotes Extensive use of internalExtensive use of internal

membranes tomembranes to

Cell functionsCell functions inincytoplasm, on plasmacytoplasm, on plasmamembranemembrane

functionsfunctions

ER,ER, golgigolgi complex,complex,mitochondria,mitochondria,

chloroplasts,chloroplasts, lysosomeslysosomes,,peroxiosomesperoxiosomes

Specific functionsSpecific functions in eachin eachorganellesorganelles


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Tubules and filamentsTubules and filamentsProkaryotesProkaryotes

Tubules andTubules andfilaments absentfilaments absent


Presence of nonPresence of non

membranousmembranouss ruc uress ruc ures n en ecytoplasmcytoplasm

Structure andStructure and

elasticityelasticity (For cellular(For cellularcontraction, motility,contraction, motility,cellular architecture)cellular architecture)


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ExocytosisExocytosis andand endocytosisendocytosisProkaryotesProkaryotes

AbsenceAbsence of theof the

processprocess


Process that allowsProcess that allows

thethe exchange ofexchange ofmaterialsmaterials within andwithin and

exterior of the cellsexterior of the cells

ExocytosisExocytosis is theis the

reverse ofreverse of endocytosisendocytosis


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OrganisationOrganisation of DNAof DNAProkaryotesProkaryotes

DNA not packed in aDNA not packed in adefinite structuredefinite structure


Packed inPacked inchromosomeschromosomes

Stored asStored as circularcircularplasmidplasmid

Relatively fewRelatively fewproteinsproteins associatedassociated

DNA: LowerDNA: Lowereukaryotes 10eukaryotes 10 50X >50X >prokaryotesprokaryotes

Most eukaryotesMost eukaryotes1000X > prokaryotes1000X > prokaryotes


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Segregation of genetic materialsSegregation of genetic materials

(to daughter cells)(to daughter cells)ProkaryotesProkaryotes

DNA replicated andDNA replicated anddistribution bydistribution by simplesimple


DNA replicated andDNA replicated andchromosomechromosome

processprocess--fissionfission

One molecule of DNAOne molecule of DNAto each daughter cellto each daughter cell

distribution through adistribution through acomplicated processcomplicated process--mitosis & meiosismitosis & meiosis


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Expression of DNAExpression of DNAProkaryotesProkaryotes

Transcribe specificTranscribe specific

segments of genetic infosegments of genetic info

EukaryotesEukaryotes Transcribe genetic info inTranscribe genetic info in

thethe nucleusnucleus into largeinto large

little or no processing andlittle or no processing andselectionselection

Size and composition ofSize and composition ofribosome(70s)ribosome(70s) totosynthesisesynthesise proteinprotein

mo ecu es anmo ecu es antransport to cytoplasmtransport to cytoplasm forforprotein synthesisprotein synthesis

Size and composition ofSize and composition ofribosome (80s)ribosome (80s) totosynthesise proteinsynthesise protein


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Comparison propertiesComparison properties

prokaryotic and eukaryotic cellsprokaryotic and eukaryotic cellsPropertiesProperties ProkaryoticProkaryotic EukaryoticEukaryotic

SizeSize Small (few m)Small (few m) Large (10Large (10--50X larger than prok)50X larger than prok)

Membrane bounded nucl.Membrane bounded nucl. NoNo YesYes

OrganellesOrganelles NoNo YesYes

MicrotubulesMicrotubules NoNo YesYes


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PropertiesPropertiesPropertiesPropertiesPropertiesPropertiesPropertiesProperties ProkaryotesProkaryotesProkaryotesProkaryotesProkaryotesProkaryotesProkaryotesProkaryotes EukaryotesEukaryotesEukaryotesEukaryotesEukaryotesEukaryotesEukaryotesEukaryotes

MicrofilamentsMicrofilamentsMicrofilamentsMicrofilamentsMicrofilamentsMicrofilamentsMicrofilamentsMicrofilaments NoNo YesYes

IntermediateIntermediateIntermediateIntermediateIntermediateIntermediateIntermediateIntermediate

filamentsfilamentsfilamentsfilamentsfilamentsfilamentsfilamentsfilamentsNoNo YesYes

Excocytosis &Excocytosis &Excocytosis &Excocytosis &Excocytosis &Excocytosis &Excocytosis &Excocytosis &

endocytosisendocytosisendocytosisendocytosisendocytosisendocytosisendocytosisendocytosisNoNo YesYes

Mode of cellMode of cellMode of cellMode of cellMode of cellMode of cellMode of cellMode of cell

divisiondivisiondivisiondivisiondivisiondivisiondivisiondivisionCell fissionCell fission Mitosis andMitosis and

meiosismeiosis


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PropertiesPropertiesPropertiesPropertiesPropertiesPropertiesPropertiesProperties ProkaryotesProkaryotesProkaryotesProkaryotesProkaryotesProkaryotesProkaryotesProkaryotes EukaryotesEukaryotesEukaryotesEukaryotesEukaryotesEukaryotesEukaryotesEukaryotesGeneticGeneticGeneticGeneticGeneticGeneticGeneticGenetic

informationinformationinformationinformationinformationinformationinformationinformationDNA moleculeDNA molecule

complexed withcomplexed withrel. few proteinsrel. few proteins

DNA moleculeDNA moleculecomplexedcomplexed

with protein towith protein to

form histonesform histonesProcessingProcessingProcessingProcessingProcessingProcessingProcessingProcessing

of RNAof RNAof RNAof RNAof RNAof RNAof RNAof RNALittleLittle MuchMuch

RibosomesRibosomesRibosomesRibosomesRibosomesRibosomesRibosomesRibosomesSmall(70s); 3Small(70s); 3RNA moleculesRNA moleculesand 55 proteinand 55 protein

Large (80s); 4Large (80s); 4RNA moleculesRNA moleculesand about 78and about 78

proteinsproteins


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Structure of Prokaryote:Structure of Prokaryote:

typical bacterial celltypical bacterial cell


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COMPARISON BETWEENCOMPARISON BETWEENANIMAL AND PLANT CELLSANIMAL AND PLANT CELLS


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ComparisonComparison between plant andbetween plant and

animal cellsanimal cellsPlantPlantPlantPlantPlantPlantPlantPlant

oo ContainsContains cell membranecell membraneand cellulose walland cellulose wall

oo Middle lamellaMiddle lamella in the cellin the cell

AnimalAnimalAnimalAnimalAnimalAnimalAnimalAnimal Cell membraneCell membrane onlyonly

NoNo middle lamellamiddle lamellawallwall

oo Cell communicates throughCell communicates throughplasmodesmataplasmodesmata

oo ContainsContains chloroplastchloroplast

oo Big vacuoleBig vacuole

Cell communicatesCell communicatesthrough through gap junctiongap junction

NoNo chloroplastchloroplast

Small vacuoleSmall vacuole


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Contd..Contd..PlantPlant

oo Tonoplast membraneTonoplast membranearound vacuolearound vacuole

AnimalAnimal

No tonoplast membraneNo tonoplast membranearound vacoulearound vacoule

oo Cytoplasm, organelle andCytoplasm, organelle andnucluesnuclues pushed aside ofpushed aside ofthe cellthe cell

oo NoNo centriolecentriole

oo Higher plantHigher plant nono cilliumcillium

oo NoNo lysosomelysosome

y op asm, organe e any op asm, organe e annucluesnuclues not pushednot pushedaside of the cellaside of the cell

CentrioleCentriole presentpresent

Cilium/flagelaCilium/flagela presentpresent

LysosomeLysosome presentpresent


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Structure of eukaryote: typical animalStructure of eukaryote: typical animalcellcell


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Structure of eukaryote: typical plant cellStructure of eukaryote: typical plant cell


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Are viruses cells?Are viruses cells? No plasma membrane ( some with hostNo plasma membrane ( some with host

cell membrane)cell membrane)

..Some with virusSome with virus--specific enzymesspecific enzymes

Dependent on host cells for livingDependent on host cells for living

processesprocesses Not cells. Living things?Not cells. Living things?


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Viroids and prions: not cellsViroids and prions: not cells EvenEven smaller than virusessmaller than viruses

Viroids:Viroids: small circular RNA, no protein,small circular RNA, no protein,

Prions:Prions: proteinaceous infectious particlesproteinaceous infectious particles

-- mad cow in cattles. Neuron associatedmad cow in cattles. Neuron associated

L1 eukaryote prokaryote

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