BacteriaBacteria

Chapter 18.1Chapter 18.1

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Three Domains of Three Domains of LifeLife

• BacteriaBacteria- - Cyanobacteria and Cyanobacteria and eubacteriaeubacteria

• ArchaeaArchaea – – prokaryotes living in prokaryotes living in extreme habitatsextreme habitats

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

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CharacteristiCharacteristics of cs of

BacteriaBacteria

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Domain BacteriaKingdom Eubacteria

Found just about everywhere

Strong cell walls w/ peptidoglycan

Some have a secondary cell wall

EubacteriaEubacteria

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Domain ArchaeaKingdom

Archaebacteria• Live in extreme

and hostile environments

• Has ribosomal proteins similar to eukaryotic cells

• Cell walls lack peptidoglycans

ArchaebacteriaArchaebacteria

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MethanogensMethanogens

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

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

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Extreme Extreme HalophilesHalophiles

• Live in very Live in very salty watersalty water

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

• Dead Sea, Dead Sea, Great Salt Great Salt Lake Lake inhabitantsinhabitants

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Thermoacidophiles Thermoacidophiles or Thermophilesor Thermophiles

• Live in Live in extremely hot extremely hot environmentsenvironments

• Found in Found in volcanic vents, volcanic vents, hot springs, hot springs, cracks on cracks on ocean floor ocean floor that leak acidthat leak acid

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Clicker Question!

Have a membrane bound nucleus and

organelles:

A: ProkaryotesB: EukaryotesC: Nokaryotes

Eubacteria vs Archaebacteria

Prokaryotic & Prokaryotic & Eukaryotic CellsEukaryotic Cells

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Earliest Earliest ProkaryotesProkaryotes

• Most numerousMost numerous organisms on Earth

• Include all bacteriabacteria

• Earliest fossils Earliest fossils datedate 2.5 billion years old

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What domain can be What domain can be found in harsh found in harsh environments like: environments like: Undersea volcanic Undersea volcanic vents, acidic hot vents, acidic hot springs, salty water?springs, salty water?

A: BacteriaA: Bacteria

B: ArchaeaB: Archaea

C: EukareaC: Eukarea15

Clicker Question!

Some eubacteria gain energy from the sun (cyanobacteria), but the rest have to gain energy by consuming other organisms. These are called:

A. HomotrophsB. HeteroeatersC. HeterotrophsD. Homoconsumers

Bacterial Bacterial StructureStructure

• MicroscopicMicroscopic• Do not have a nucleus Do not have a nucleus

or membrane-bound or membrane-bound organellesorganelles

• Have ribosomesHave ribosomes• Single, circular Single, circular

chromosomechromosome• Have plasmids Have plasmids • UnicellularUnicellular 17

PLASMIDSPLASMIDS

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Bacterial Cell

Sticky Bacterial Sticky Bacterial CapsuleCapsule

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Prevents drying out, allows it to attach to other surfaces, prevents it from being engulfed, & shelters it from antibiotics

Pili in ConjugationPili in Conjugation

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Hairlike structures that help them attach to surfaces and allow for transfer of genetic material between two bacteria

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FlagellaFlagella• Bacteria that Bacteria that

are motile are motile have have appendages appendages called flagellacalled flagella

• A bacteria can A bacteria can have one or have one or many flagellamany flagella

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Monotrichous Lophotrichous

Amphitrichous Peritrichous

Clicker Question!Clicker Question!What structure does this What structure does this

bacterium use for motility?bacterium use for motility?A: FlagellaA: FlagellaB: CiliaB: CiliaC: PiliC: Pili

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Bacterial Bacterial ShapesShapes

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Shapes Used to Shapes Used to ClassifyClassify

• Bacillus:Bacillus:

• Coccus:Coccus:

• Spirillum:Spirillum:

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Grouping of BacteriaGrouping of Bacteria•Diplo-Diplo-

•Strepto-Strepto-

•Staphylo-Staphylo-

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Clicker Question!Clicker Question!

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What shape and grouping describes the bacteria pointed out below?A: Staphalacoccus

B: StreptobacillusC: Diplococcus

Staphylococcus Staphylococcus BacterialBacterial

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Streptococcus Streptococcus Causes Strep ThroatCauses Strep Throat

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Bacillus - Bacillus - E. E. colicoli

StreptobacilliStreptobacilli

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SpirillumSpirillum

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LeptospiraLeptospira

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Clicker Question!

A. Staphylococcus

B. Coccus

C. Spirillum

D. Bacillus

E. Streptococcus

F. Diplococcus

1. _________

2. _________

3. _________

4. _________

5. _________

6. _________

Gram StainingGram Staining

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

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

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

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Gram PositiveGram Positive• Have a thick Have a thick

layer of layer of peptidoglycan peptidoglycan

• Stain purpleStain purple• Can be Can be

treated with treated with antibioticsantibiotics

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Gram Negative Gram Negative BacteriaBacteria

• Thin layer of Thin layer of peptidoglycan in cell wallpeptidoglycan in cell wall

• Outer layer of lipidsOuter layer of lipids• Stain pinkStain pink• Hard to treat with Hard to treat with

antibioticsantibiotics

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Gram NegativeGram Negative• Rickettsiae are Rickettsiae are

bacteria bacteria carried by carried by ticksticks

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

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Clicker Question!

Which type of bacteria is susceptible to antibiotics?

A: Gram Positive (Dark Purple)B: Gram Negative (Light Pink)

2 kinds of reproduction:

• Binary fission

• Conjugation

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

daughter cellsdaughter cells

Binary Fission Binary Fission E. E. colicoli

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Clicker Question!Clicker Question!

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What kind of reproduction is depicted in the photo below?

A: AsexualB: ConjugationC: Binary fission

Bacterial Bacterial RespirationRespiration

• AnaerobesAnaerobes

• AerobesAerobes

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Modes of NutritionModes of Nutrition• Saprobes Saprobes – feed on – feed on

dead organic matterdead organic matter• ParasitesParasites – feed on a – feed on a

host cellhost cell• PhotoautotrophPhotoautotroph – use – use

sunlight to make foodsunlight to make food• ChemoautotrophChemoautotroph – –

oxidize inorganic matter oxidize inorganic matter such as iron or sulfur to such as iron or sulfur to make foodmake food

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Bacteria and Survival

Bacterial Survival:Mutations

•Reproduce quickly•Low rate to fix mistakes in DNA

•Leads to increase in genetic diversity

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Bacterial Survival:Endospores

Ecology of Bacteria

All living things need Nitrogen

Bacteria fix nitrogen to make it usable!

Bacteria decompose and recycle nutrients!

Normal Flora•Harmless•Live on, in, and around you•E. coli helps make Vitamin K used to help clot blood

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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Bacteria make Bacteria make foodfood

•YogurtYogurt•CheeseCheese•ButtermilkButtermilk•PicklesPickles•ChocolateChocolate

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Bacteria make Medicine

•Vitamins•Antibiotics:

–Streptomycin–Bacitracin–Tetracycline–Vancomycin

PathogensPathogens

STD: Syphilis, gonorrhea, ChlamydiaSTD: Syphilis, gonorrhea, Chlamydia

Respiratory: Strep throat, pneumonia, Respiratory: Strep throat, pneumonia, whooping cough, tuberculosis, whooping cough, tuberculosis, anthraxanthrax

Skin: Acne, boilsSkin: Acne, boils

Digestive: Gastroenteritis, food Digestive: Gastroenteritis, food poisoning, cholerapoisoning, cholera

Nervous: Botulism, tetanus, bacterial Nervous: Botulism, tetanus, bacterial meningitismeningitis

Other: Lyme disease, typhoid feverOther: Lyme disease, typhoid fever 59