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BacteriaBacteria

Structure and FunctionStructure and Function

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Prokaryotic & Prokaryotic & Eukaryotic CellsEukaryotic Cells

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Classification Classification of Lifeof Life

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Three Domains of LifeThree Domains of Life• ArchaeaArchaea – –

prokaryotes living in prokaryotes living in extreme habitatsextreme habitats

• BacteriaBacteria- - Cyanobacteria and Cyanobacteria and eubacteriaeubacteria

• EukaryaEukarya – – Protozoans, fungi, Protozoans, fungi, plants, & animalsplants, & animals

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Kingdoms of Kingdoms of BacteriaBacteria

Archaebacteria:Archaebacteria: Found in Found in harsh harsh

environmentsenvironments Undersea Undersea volcanic volcanic

ventsvents, acidic , acidic hot hot springssprings, , saltysalty water water

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ArchaebacteriaArchaebacteria

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Kingdoms of Kingdoms of BacteriaBacteria

Eubacteria:Eubacteria: Called the Called the true true

bacteriabacteria Most bacteriaMost bacteria are in are in

this groupthis group Include photosynthetic Include photosynthetic

CyanobacteriaCyanobacteria

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EubacteriaEubacteria

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CharacteristicCharacteristics of Bacterias of Bacteria

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Bacterial StructureBacterial Structure

• Microscopic Microscopic prokaryotesprokaryotes• No No nucleus or nucleus or

membrane-bound membrane-bound organellesorganelles

• Contain Contain ribosomesribosomes• Single, circular Single, circular

chromosome in chromosome in nucleoid nucleoid regionregion

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Bacterial Cell

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ProtectionProtection•Cell Wall made of Cell Wall made of

PeptidoglycanPeptidoglycan•May have a sticky May have a sticky

coating called the coating called the Capsule Capsule for for attachment to host attachment to host or other bacteriaor other bacteria

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Sticky Bacterial Sticky Bacterial CapsuleCapsule

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Bacterial Bacterial StructureStructure

•Have small rings of Have small rings of DNA called DNA called PlasmidsPlasmids

•UnicellularUnicellular•SmallSmall in size (0.5 to in size (0.5 to

2μm 2μm [micometer][micometer]))

PLASMIDSPLASMIDS

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Bacterial StructureBacterial Structure

•Infoldings Infoldings of cell of cell membrane carry onmembrane carry on photosynthesis & photosynthesis & cellular respirationcellular respiration

•Infoldings called Infoldings called MesosomesMesosomes

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MesosomesMesosomesMESOSOME

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Bacterial StructureBacterial Structure

•Most grow best at Most grow best at pH pH of 6.5 to 7.0of 6.5 to 7.0

•Many act as Many act as decomposersdecomposers recycling nutrientsrecycling nutrients

•Some cause Some cause diseasedisease

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Staphylococcus Staphylococcus BacterialBacterial

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Beneficial Uses of Beneficial Uses of BacteriaBacteria

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Useful BacteriaUseful Bacteria

• Some Some bacteria bacteria can can degrade degrade oiloil

• Used to Used to clean up clean up oil spillsoil spills

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Environmental Clean-upEnvironmental Clean-up• Some bacteria eat oil and turn Some bacteria eat oil and turn

it into environmentally friendly it into environmentally friendly chemicals. These bacteria are chemicals. These bacteria are dumped into waters dumped into waters contaminated by oil spills.contaminated by oil spills.

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Environmental RecyclingEnvironmental Recycling

• Bacteria are Bacteria are decomposers: they decomposers: they break down dead break down dead organisms into smaller organisms into smaller chemicals which then chemicals which then go back into the soil.go back into the soil.

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DigestionDigestion• Many bacteria, such as human Many bacteria, such as human

E. coli, live a warm and cozy E. coli, live a warm and cozy life in your intestines. They life in your intestines. They help digest your food and help digest your food and make vitamins, such as make vitamins, such as Vitamin K (which is necessary Vitamin K (which is necessary for blood clotting).for blood clotting).

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Digestive HealthDigestive Health

• Beneficial bacteria, such as Beneficial bacteria, such as Lactobacillus, keep the “bad” Lactobacillus, keep the “bad” bacteria in check, by bacteria in check, by competing with them for competing with them for nutrients.nutrients.

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MedicinesMedicines

• The pharmaceutical The pharmaceutical industry uses some forms industry uses some forms of bacteria to make of bacteria to make vitamins and antibiotics.vitamins and antibiotics.

• Other bacteria can be used Other bacteria can be used to produce insulin, which to produce insulin, which can be collected and given can be collected and given to people with diabetes.to people with diabetes.

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Useful BacteriaUseful Bacteria•Other uses Other uses

for bacteria for bacteria include include making making yogurt, yogurt, cheese, and cheese, and buttermilk.buttermilk.

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Fuel ProductionFuel Production

• Archaebacteria produce Archaebacteria produce methane gas, which makes methane gas, which makes up 20% of the world’s up 20% of the world’s natural gas used for fuel.natural gas used for fuel.

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FlagellaFlagella• Bacteria that Bacteria that

are are motile motile have have appendages appendages called called flagellaflagella

• Attached byAttached by Basal BodyBasal Body

• A bacteria can A bacteria can have have one or one or manymany flagella flagella

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Monotrichous Lophotrichous

Amphitrichous Peritrichous

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Question:Question:

What is this type of What is this type of bacteria ?bacteria ?

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PiliPili• Short proteinShort protein

appendagesappendages• SmallerSmaller than flagella than flagella• AdhereAdhere bacteria to bacteria to

surfacessurfaces• Used in Used in conjugationconjugation for for

Exchange of genetic Exchange of genetic informationinformation

• AidAid Flotation Flotation by by increasing buoyancyincreasing buoyancy

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Pili in ConjugationPili in Conjugation

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Bacterial Bacterial ShapesShapes

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Shapes Are Used to Shapes Are Used to ClassifyClassify

• Bacillus: Bacillus: Rod shapedRod shaped

• Coccus: Coccus: Spherical (round)Spherical (round)

• Vibrio: Vibrio: Comma shaped Comma shaped with flagellawith flagella

• Spirillum: Spirillum: Spiral shapeSpiral shape

• Spirochete: Spirochete: wormlike spiral wormlike spiral shapeshape

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Grouping of BacteriaGrouping of Bacteria

•DiploDiplo- Groups of - Groups of twotwo

•StreptoStrepto- chains- chains•StaphyloStaphylo- Grapelike - Grapelike

clustersclusters

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DiplococcusDiplococcus

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Streptococcus Causes Streptococcus Causes Strep ThroatStrep Throat

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StaphylococcusStaphylococcus

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Bacillus - E. coliBacillus - E. coli

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Bacterial Bacterial KingdomsKingdoms

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ArchaebacteriaArchaebacteria• Lack peptidoglycanLack peptidoglycan in in

cell wallscell walls• Have Have different lipidsdifferent lipids in in

their cell membranetheir cell membrane• Different types of Different types of

ribosomesribosomes• Very Very different genedifferent gene

sequencessequences

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ArchaebacteriaArchaebacteria

• Archaebacteria can live in Archaebacteria can live in extremely harsh extremely harsh environmentsenvironments

• They They do not require oxygendo not require oxygen and can live in and can live in extremely extremely saltysalty environments as well environments as well as as extremely hotextremely hot environmentsenvironments

• Called the Called the Ancient bacteriaAncient bacteria

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ArchaebacteriaArchaebacteria

•Subdivided into 3 Subdivided into 3 groups:groups:

MethanogensMethanogensThermoacidophileThermoacidophile

ssExtreme Extreme

HalophilesHalophiles

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MethanogensMethanogens

• Live in Live in anaerobic anaerobic environments (no oxygen)environments (no oxygen)

• Get energy by Get energy by changing changing HH22 & CO & CO22 into methane into methane gasgas

• Found in Found in swampsswamps, , sewage sewage treatmenttreatment plants, plants, digestive tractsdigestive tracts of animals of animals

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MethanogensMethanogens

• Break down Break down cellulose in cellulose in a cow’sa cow’s stomachstomach

• Produce Produce marsh marsh (methane) (methane) gasgas

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Extreme HalophilesExtreme Halophiles

• Live in very Live in very salty watersalty water

• Use Use salt to salt to generate generate ATPATP (energy) (energy)

• Dead Sea, Dead Sea, Great Salt Great Salt LakeLake inhabitantsinhabitants

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Thermoacidophiles or Thermoacidophiles or ThermophilesThermophiles

• Live in Live in extremely hot extremely hot environmentsenvironments

• Found in Found in volcanicvolcanic vents, vents, hot springs, hot springs, cracks on cracks on ocean floor that ocean floor that leak acidleak acid

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Kingdom Kingdom EubacteriaEubacteria

True BacteriaTrue Bacteria

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CharacteristicsCharacteristics

• 3 basic shapes3 basic shapes (coccus, (coccus, bacillus, spirilla)bacillus, spirilla)

• Most are Most are heterotrophic heterotrophic (can’t make their own (can’t make their own food)food)

• May be May be aerobic or aerobic or anaerobicanaerobic

• Identified by Identified by Gram Gram stainingstaining

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Gram StainingGram Staining

• Developed in Developed in 1884 by 1884 by Hans GramHans Gram

• Bacteria treated with Bacteria treated with purple Crystal Violet & purple Crystal Violet & red Safranin stainsred Safranin stains

• Cell wallsCell walls either stain either stain purple or reddish pinkpurple or reddish pink

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Gram PositiveGram Positive

• Have Have thick thick layer of layer of peptidoglycanpeptidoglycan (protein-sugar (protein-sugar complex)complex)

• Single lipid Single lipid layerlayer

• Stain Stain purplepurple• Can be treated Can be treated

with with antibioticsantibiotics

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Gram Positive Gram Positive BacteriaBacteria

Lactobacilli Lactobacilli (makes yogurt & (makes yogurt & buttermilk)buttermilk)

Actinomycetes (Actinomycetes (make make antibiotics)antibiotics)

Clostridium Clostridium (lockjaw (lockjaw bacteria)bacteria)

Streptococcus Streptococcus (strep throat)(strep throat)Staphylococcus (Staphylococcus (staph staph

infections)infections)

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Gram Negative Gram Negative BacteriaBacteria

• Thin layer of peptidoglycanThin layer of peptidoglycan in cell wallin cell wall

• Extra Extra thick layer of lipidsthick layer of lipids• Stain Stain pink or reddishpink or reddish• Hard to treatHard to treat with antibiotics with antibiotics• Some Some photosyntheticphotosynthetic but but

make sulfur not oxygenmake sulfur not oxygen• Some Some fix nitrogenfix nitrogen for plants for plants

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Gram NegativeGram Negative

• Rhizobacteria Rhizobacteria grow in root grow in root nodules of nodules of legumeslegumes (soybeans, (soybeans, peanuts)peanuts)

• Fix NFix N22 from air from air into usable into usable ammoniaammonia

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Gram NegativeGram Negative

• Rickettsiae Rickettsiae are are parasitic parasitic bacteria bacteria carried by tickscarried by ticks

• Cause Cause Lyme Lyme disease & disease & Rocky Rocky Mountain Mountain Spotted FeverSpotted Fever

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CyanobacteriaCyanobacteria

• Gram Gram negativenegative• PhotosyntheticPhotosynthetic• Called Called blue-green blue-green

bacteriabacteria• Contain Contain phycocyaninphycocyanin

(red-blue) pigments & (red-blue) pigments & chlorophyllchlorophyll

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CyanobacteriaCyanobacteria

• May be red, yellow, brown, black, May be red, yellow, brown, black, or blue-greenor blue-green

• May grow in May grow in chainschains (Oscillatoria) (Oscillatoria)• Have Have HeterocystsHeterocysts to help fix N to help fix N22

• First to re-enterFirst to re-enter devastated areas devastated areas• Some cause Some cause EutrophicationEutrophication (use (use

up O2 when die & decompose in up O2 when die & decompose in water)water)

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CyanobacteriaCyanobacteria

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SpirochetesSpirochetes

• Gram Gram positivepositive• Flagella at each Flagella at each

endend• Move in Move in corkscrewcorkscrew

motionmotion• Some Some aerobicaerobic; ;

others others anaerobicanaerobic• May be May be free living, free living,

parasitic, or parasitic, or symbioticsymbiotic

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Enteric BacteriaEnteric Bacteria

• Gram Gram negativenegative• Can live in Can live in aerobic & aerobic &

anaerobicanaerobic habitats habitats• Includes Includes E. coliE. coli in in

intestinesintestines• Salmonella Salmonella – causes food – causes food

poisoningpoisoning

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ChemoautotrophsChemoautotrophs

• Gram Gram negativenegative• Obtain energy from Obtain energy from

minerals like ironminerals like iron• Found in Found in freshwater freshwater

pondsponds

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Nutrition, Nutrition, Respiration, Respiration,

and and ReproductionReproduction

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Modes of NutritionModes of Nutrition

• Saprobes Saprobes – 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 as inorganic matter such as iron or sulfur to make foodiron or sulfur to make food

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Methods of Methods of RespirationRespiration

• Obligate AerobesObligate Aerobes – require – require OO22 (tuberculosis bacteria) (tuberculosis bacteria)

• Obligate AnaerobesObligate Anaerobes – die if – die if OO22 is present (tetanus) is present (tetanus)

• Facultative AnaerobesFacultative Anaerobes – – don’t need Odon’t need O22, but aren’t , but aren’t killed by it (E. coli)killed by it (E. coli)

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Bacterial RespirationBacterial Respiration

• AnaerobesAnaerobes carry on carry on fermentatiofermentationn

• Aerobes Aerobes carry on carry on cellular cellular respirationrespiration

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ReproductionReproduction• Bacteria reproduce Bacteria reproduce

asexually by binary fissionasexually by binary fission• Single chromosome Single chromosome

replicatesreplicates & then cell & then cell dividesdivides

• RapidRapid• All new cells All new cells identical identical

(clones)(clones)

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Cellular organism copies it’s genetic information Cellular organism copies it’s genetic information then splits into two identical daughter cellsthen splits into two identical daughter cells

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Binary Fission E. coliBinary Fission E. coli

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ReproductionReproduction

• Bacteria reproduce Bacteria reproduce sexually by Conjugationsexually by Conjugation

• Form aForm a tube between 2 tube between 2 bacteria bacteria to exchangeto exchange genetic materialgenetic material

• Held together byHeld together by pili pili• New cellsNew cells NOT identical NOT identical

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ConjugationConjugation

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Spore FormationSpore Formation

• Form Form endosporeendospore whenever when whenever when habitat conditions habitat conditions become become harsh harsh (little food)(little food)

• Able to Able to survive for survive for long periods of long periods of timetime as as endospermendosperm

• Difficult to destroy Difficult to destroy (heat resistant)(heat resistant)

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Transduction & Transduction & TransformationTransformation

• Genetically changeGenetically change bacteria bacteria• May become May become antibiotic antibiotic

resistantresistant• Transformed bacteriaTransformed bacteria pick up pick up

pieces of DNA from dead pieces of DNA from dead bacterial cellsbacterial cells

• TransductionTransduction – viruses carry – viruses carry foreign DNA to bacteria; foreign DNA to bacteria; used used to make insulinto make insulin

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Pathenogenic Pathenogenic BacteriaBacteria

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PathogensPathogens

• Called Called germs or microbesgerms or microbes• Cause Cause diseasedisease• May produce May produce poisons or poisons or

toxinstoxins• EndotoxinsEndotoxins released after released after

bacteria die (bacteria die (E. coliE. coli))• Exotoxins Exotoxins released by Gram released by Gram

+ bacteria (+ bacteria (C. tetaniC. tetani))