3. 3
Cellular EvolutionCellular Evolution
• Current evidenceCurrent evidence
indicates thatindicates that eukaryoteseukaryotes
evolved from prokaryotesevolved from prokaryotes
between 1 and 1.5 billionbetween 1 and 1.5 billion
years agoyears ago
• Two theories:Two theories:
1.1. Infolding theoryInfolding theory
2.2. Endosymbiotic theoryEndosymbiotic theory
4. 4
Infolding TheoryInfolding Theory
• TheThe infolding of theinfolding of the
prokaryotic plasmaprokaryotic plasma
membrane gave rise tomembrane gave rise to
eukaryotic organelles.eukaryotic organelles.
infolding organelle
5. 5
Endosymbiotic TheoryEndosymbiotic Theory
• Endosymbiosis refers toEndosymbiosis refers to oneone
species living within anotherspecies living within another(the(the
host)host)
• Movement ofMovement of smallersmaller
photosyntheticphotosynthetic && heterotrophicheterotrophic
prokaryotesprokaryotes into larger prokaryoticinto larger prokaryotic
host cellshost cells
• FormedFormed cell organellescell organelles chloroplast
mitochondria
9. 9
Three Domains ofThree Domains of
LifeLife
• ArchaeaArchaea ––
prokaryotes living inprokaryotes living in
extreme habitatsextreme habitats
• BacteriaBacteria--
Cyanobacteria andCyanobacteria and
eubacteriaeubacteria
• EukaryaEukarya ––
Protozoans, fungi,Protozoans, fungi,
plants, & animalsplants, & animals
10. 10
Kingdoms of BacteriaKingdoms of Bacteria
Archaebacteria:Archaebacteria:
Found inFound in harshharsh
environmentsenvironments
UnderseaUndersea volcanic ventsvolcanic vents,,
acidicacidic hot springshot springs,, saltysalty
waterwater
12. 12
Kingdoms of BacteriaKingdoms of Bacteria
Eubacteria:Eubacteria:
Called theCalled the truetrue
bacteriabacteria
Most bacteriaMost bacteria are inare in
this groupthis group
Include photosyntheticInclude photosynthetic
CyanobacteriaCyanobacteria
17. 17
ProtectionProtection
• Cell Wall made ofCell Wall made of
PeptidoglycanPeptidoglycan
• May have a stickyMay have a sticky
coating called thecoating called the
CapsuleCapsule forfor
attachment to host orattachment to host or
other bacteriaother bacteria
19. 19
BacterialBacterial
StructureStructure
• Have small rings ofHave small rings of
DNA calledDNA called PlasmidsPlasmids
• UnicellularUnicellular
• SmallSmall in size (0.5 toin size (0.5 to
2μm)2μm)
PLASMIDSPLASMIDS
23. 23
Bacterial StructureBacterial Structure
• Most grow best atMost grow best at
pH of 6.5 to 7.0pH of 6.5 to 7.0
• Many act asMany act as
decomposersdecomposers recyclingrecycling
nutrientsnutrients
• Some causeSome cause diseasedisease
25. 25
Useful BacteriaUseful Bacteria
• SomeSome
bacteriabacteria
cancan
degrade oildegrade oil
• Used toUsed to
clean upclean up oiloil
spillsspills
26. 26
Useful BacteriaUseful Bacteria
• Other usesOther uses
for bacteriafor bacteria
includeinclude
makingmaking
yogurt,yogurt,
cheese, andcheese, and
buttermilk.buttermilk.
27. 27
FlagellaFlagella
• Bacteria thatBacteria that
areare motilemotile havehave
appendagesappendages
calledcalled flagellaflagella
• Attached byAttached by
Basal BodyBasal Body
• A bacteria canA bacteria can
havehave one orone or
manymany flagellaflagella
29. 29
FlagellaFlagella
• Made ofMade of FlagellinFlagellin
• Used forUsed for ClassificationClassification
• Monotrichous:Monotrichous: 1 flagella1 flagella
• Lophotrichous:Lophotrichous: tuft attuft at
one endone end
• Amphitrichous:Amphitrichous: tuft attuft at
both endsboth ends
• Peritrichous:Peritrichous: all aroundall around
bacteriabacteria
32. 32
PiliPili
• Short proteinShort protein appendagesappendages
• SmallerSmaller than flagellathan flagella
• AdhereAdhere bacteria tobacteria to
surfacessurfaces
• Used inUsed in conjugationconjugation forfor
Exchange of geneticExchange of genetic
informationinformation
• AidAid FlotationFlotation byby
increasing buoyancyincreasing buoyancy
37. 37
Grouping of BacteriaGrouping of Bacteria
• DiploDiplo- Groups of- Groups of
twotwo
• StreptoStrepto- chains- chains
• StaphyloStaphylo- Grapelike- Grapelike
clustersclusters
50. 50
ArchaebacteriaArchaebacteria
• Lack peptidoglycanLack peptidoglycan in cellin cell
wallswalls
• HaveHave different lipidsdifferent lipids inin
their cell membranetheir cell membrane
• Different types ofDifferent types of
ribosomesribosomes
• VeryVery different genedifferent gene
sequencessequences
51. 51
ArchaebacteriaArchaebacteria
• Archaebacteria can live inArchaebacteria can live in
extremely harshextremely harsh
environmentsenvironments
• TheyThey do not require oxygendo not require oxygen
and can live inand can live in extremelyextremely
saltysalty environments as well asenvironments as well as
extremely hotextremely hot environmentsenvironments
• Called theCalled the Ancient bacteriaAncient bacteria
53. 53
MethanogensMethanogens
• Live inLive in anaerobicanaerobic
environments (no oxygen)environments (no oxygen)
• Get energy byGet energy by changing Hchanging H22
& CO& CO22 into methane gasinto methane gas
• Found inFound in swampsswamps,, sewagesewage
treatmenttreatment plants,plants, digestivedigestive
tractstracts of animalsof animals
55. 55
Extreme HalophilesExtreme Halophiles
• Live in veryLive in very
salty watersalty water
• UseUse salt tosalt to
generategenerate
ATPATP (energy)(energy)
• Dead Sea,Dead Sea,
Great SaltGreat Salt
LakeLake
inhabitantsinhabitants
56. 56
Thermoacidophiles orThermoacidophiles or
ThermophilesThermophiles
• Live inLive in
extremely hotextremely hot
environmentsenvironments
• Found inFound in
volcanicvolcanic vents,vents,
hot springs,hot springs,
cracks on oceancracks on ocean
floor that leakfloor that leak
acidacid
58. 58
CharacteristicsCharacteristics
• 3 basic shapes3 basic shapes (coccus,(coccus,
bacillus, spirilla)bacillus, spirilla)
• Most areMost are heterotrophicheterotrophic
(can’t make their own food)(can’t make their own food)
• May beMay be aerobic oraerobic or
anaerobicanaerobic
• Identified byIdentified by Gram stainingGram staining
59. 59
Gram StainingGram Staining
• Developed inDeveloped in 1884 by1884 by
Hans GramHans Gram
• Bacteria treated withBacteria treated with
purple Crystal Violet & redpurple Crystal Violet & red
Safranin stainsSafranin stains
• Cell wallsCell walls either staineither stain
purple or reddish pinkpurple or reddish pink
60. 60
Gram PositiveGram Positive
• HaveHave thick layerthick layer
of peptidoglycanof peptidoglycan
(protein-sugar(protein-sugar
complex)complex)
• Single lipidSingle lipid
layerlayer
• StainStain purplepurple
• Can be treatedCan be treated
withwith antibioticsantibiotics
62. 62
Gram NegativeGram Negative
BacteriaBacteria
• Thin layer of peptidoglycanThin layer of peptidoglycan inin
cell wallcell wall
• ExtraExtra thick layer of lipidsthick layer of lipids
• StainStain pink or reddishpink or reddish
• Hard to treatHard to treat with antibioticswith antibiotics
• SomeSome photosyntheticphotosynthetic butbut
make sulfur not oxygenmake sulfur not oxygen
• SomeSome fix nitrogenfix nitrogen for plantsfor plants
63. 63
Gram NegativeGram Negative
• RhizobacteriaRhizobacteria
grow in rootgrow in root
nodules ofnodules of
legumeslegumes
(soybeans,(soybeans,
peanuts)peanuts)
• Fix NFix N22 from airfrom air
into usableinto usable
ammoniaammonia
66. 66
CyanobacteriaCyanobacteria
• May be red, yellow, brown, black,May be red, yellow, brown, black,
or blue-greenor blue-green
• May grow inMay grow in chainschains ((OscillatoriaOscillatoria))
• HaveHave HeterocystsHeterocysts to help fix Nto help fix N22
• First to re-enterFirst to re-enter devastateddevastated
areasareas
• Some causeSome cause EutrophicationEutrophication (use up(use up
O2 when die & decompose inO2 when die & decompose in
water)water)
68. 68
SpirochetesSpirochetes
• GramGram positivepositive
• Flagella at each endFlagella at each end
• Move inMove in corkscrewcorkscrew
motionmotion
• SomeSome aerobicaerobic;;
othersothers anaerobicanaerobic
• May beMay be free living,free living,
parasitic, orparasitic, or
symbioticsymbiotic
69. 69
Enteric BacteriaEnteric Bacteria
• GramGram negativenegative
• Can live inCan live in aerobic &aerobic &
anaerobicanaerobic habitatshabitats
• IncludesIncludes E. coliE. coli inin
intestinesintestines
• SalmonellaSalmonella –– causes foodcauses food
poisoningpoisoning
72. 72
Modes of NutritionModes of Nutrition
• SaprobesSaprobes – feed on dead– feed on dead
organic matterorganic matter
• ParasitesParasites – feed on a host– feed on a host
cellcell
• PhotoautotrophPhotoautotroph – use– use
sunlight to make foodsunlight to make food
• ChemoautotrophChemoautotroph – oxidize– oxidize
inorganic matter such asinorganic matter such as
iron or sulfur to make foodiron or sulfur to make food
73. 73
Methods of RespirationMethods of Respiration
• Obligate AerobesObligate Aerobes – require O– require O22
(tuberculosis bacteria)(tuberculosis bacteria)
• Obligate AnaerobesObligate Anaerobes – die if– die if
OO22 is present (tetanus)is present (tetanus)
• Facultative AnaerobesFacultative Anaerobes – don’t– don’t
need Oneed O22, but aren’t killed by, but aren’t killed by
it (it (E. coliE. coli))
75. 75
ReproductionReproduction
• Bacteria reproduceBacteria reproduce
asexually by binary fissionasexually by binary fission
• Single chromosomeSingle chromosome
replicatesreplicates & then cell& then cell
dividesdivides
• RapidRapid
• All new cellsAll new cells identicalidentical
(clones)(clones)
76. 76
Cellular organism copies it’s genetic informationCellular organism copies it’s genetic information
then splits into two identical daughter cellsthen splits into two identical daughter cells
78. 78
ReproductionReproduction
• Bacteria reproduceBacteria reproduce
sexually by Conjugationsexually by Conjugation
• Form aForm a tube between 2tube between 2
bacteriabacteria to exchangeto exchange
genetic materialgenetic material
• Held together byHeld together by pilipili
• New cellsNew cells NOT identicalNOT identical
80. 80
Spore FormationSpore Formation
• FormForm endosporeendospore
whenever whenwhenever when
habitat conditionshabitat conditions
becomebecome harshharsh
(little food)(little food)
• Able toAble to survive forsurvive for
long periods oflong periods of
timetime as endospermas endosperm
• Difficult toDifficult to
destroy (heatdestroy (heat
resistant)resistant)
81. 81
Transduction &Transduction &
TransformationTransformation
• Genetically changeGenetically change bacteriabacteria
• May becomeMay become antibiotic resistantantibiotic resistant
• Transformed bacteriaTransformed bacteria pick uppick up
pieces of DNA from deadpieces of DNA from dead
bacterial cellsbacterial cells
• TransductionTransduction – viruses carry– viruses carry
foreign DNA to bacteria;foreign DNA to bacteria; usedused
to make insulinto make insulin
83. 83
PathogensPathogens
• CalledCalled germs or microbesgerms or microbes
• CauseCause diseasedisease
• May produceMay produce poisons orpoisons or
toxinstoxins
• EndotoxinsEndotoxins released afterreleased after
bacteria die (bacteria die (E. coliE. coli))
• ExotoxinsExotoxins released by Gramreleased by Gram
+ bacteria (+ bacteria (C. tetaniC. tetani))
