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