BacteriaBacteriaChapter 23Chapter 23

Bacterial Bacterial ClassificationClassification

Section 23.1Section 23.1

REVIEWREVIEW: All Bacteria : All Bacteria are Prokaryotesare Prokaryotes

ProkaryotesProkaryotes::

““Before nucleus”Before nucleus”

No nucleusNo nucleus

No membrane No membrane bound organellesbound organelles

EukaryotesEukaryotes::

““True nucleus”True nucleus”

Have nucleusHave nucleus

Have membrane Have membrane bound organellesbound organelles

Two Domains of BacteriaTwo Domains of BacteriaDIFFERENCES BASED UPON RNA DIFFERENCES BASED UPON RNA

MAKEUPMAKEUP

1.1. Domain BacteriaDomain Bacteria Kingdom EubacteriaKingdom Eubacteria

2.2. Domain ArchaeaDomain Archaea Kingdom ArchaebacteriaKingdom Archaebacteria More related to eukaryotes More related to eukaryotes

based upon rRNA & gene comparisonbased upon rRNA & gene comparison

1. Domain Archaea1. Domain Archaea Lack Lack peptidoglycanpeptidoglycan (protein- (protein-

carbohydrate compound) in cell wallcarbohydrate compound) in cell wall

Usually located in Usually located in extreme conditions extreme conditions like: swamps, salt lakes, and hot like: swamps, salt lakes, and hot springssprings

Three main types:Three main types: A. MethanogensA. Methanogens B. Extreme halophliesB. Extreme halophlies C. ThermoacidophilesC. Thermoacidophiles

Pyrodictium occultum is a  marine organism commonly found in deep-sea hydrothermal vents.

A. MethanogensA. Methanogens Energy source: Energy source: from converting Hfrom converting H2 2

and COand CO22 into methane gas. into methane gas. Live in areas Live in areas absent of oxygen absent of oxygen like like

swamps, sewage, and intestinal tractswamps, sewage, and intestinal tract

B. Extreme HalophilesB. Extreme Halophiles

Salt loving bacteriaSalt loving bacteria

LocationLocation:: anywhere there is a high salt anywhere there is a high salt concentrations like the Great Salt Lake concentrations like the Great Salt Lake and the Dead Sea.and the Dead Sea.

Energy sourceEnergy source:: salt need for them to salt need for them to make ATPmake ATP

C. ThermoacidophilesC. Thermoacidophiles

hot and acidichot and acidic enviornmentsenviornments

They are found in such They are found in such places as acidic sulfur places as acidic sulfur springs, undersea springs, undersea vents (smokers) and vents (smokers) and volcanoesvolcanoes

2. Domain Bacteria2. Domain Bacteria Most abundant domain!Most abundant domain! Examples: Examples: Cyanobacteria, Cyanobacteria,

chlamydia, Lyme Disease, chlamydia, Lyme Disease, botulism, TB, E. coli, anthrax, botulism, TB, E. coli, anthrax, nitrogen-fixing bacterianitrogen-fixing bacteria

Classified based on:Classified based on:

Gram stainGram stain ShapeShape Biochemical propertiesBiochemical properties

Gram StainGram Stain

Gram Positive Gram Positive BacteriaBacteria

Simple cell wall Simple cell wall with lots of with lots of peptidoglycanpeptidoglycan

Stains purpleStains purple

Gram Negative Gram Negative BacteriaBacteria

Complex cell wall Complex cell wall with little with little peptidoglycanpeptidoglycan

Stains pinkStains pink

Bacterial ShapesBacterial Shapes Spirilla (spiral-shaped)Spirilla (spiral-shaped)

Bacilli (rod-shaped)Bacilli (rod-shaped)

Cocci (sphere-shaped)Cocci (sphere-shaped) Streptococci – long Streptococci – long

chainschains Staphylococci - clustersStaphylococci - clusters

Bacterial GroupsBacterial Groups

1.1. ProteobacteriaProteobacteria

2.2. Gram-Positive Gram-Positive BacteriaBacteria

3.3. CyanobacteriaCyanobacteria

4.4. SpriochetesSpriochetes

5.5. ChlamydiaChlamydia

1. Proteobacteria1. Proteobacteria

Largest and most diverse groupLargest and most diverse group Many live symbiotically with other Many live symbiotically with other

organismsorganisms Nitrogen-fixing bacteria Nitrogen-fixing bacteria

Some cause diseasesSome cause diseases Rocky Mountain spotted feverRocky Mountain spotted fever Stomach ulcersStomach ulcers Foodborne illnessesFoodborne illnesses

2. Gram-Positive 2. Gram-Positive BacteriaBacteria

Some cause diseasesSome cause diseases Strep throatStrep throat Botulism (Botox)Botulism (Botox) AnthraxAnthrax TBTB LeprosyLeprosy

A few make A few make antibioticsantibiotics that kill that kill other bacteriaother bacteria

3. Cyanobacteria3. Cyanobacteria

Undergo Undergo photosynthesisphotosynthesis for for energyenergy

Simplest life requirementsSimplest life requirements

First oxygen-producing First oxygen-producing organisms on Earth!organisms on Earth!

4. Spirochetes4. Spirochetes

Gram-negativeGram-negative

Spiral-shaped bacteriaSpiral-shaped bacteria

ExamplesExamples: syphilis & Lyme disease: syphilis & Lyme disease

5. Chlamydia5. Chlamydia

Gram-negativeGram-negative Coccoid shaped, no peptidoglycan Coccoid shaped, no peptidoglycan

Causes a STD that lives inside Causes a STD that lives inside animalsanimals

Biology of Biology of ProkaryotesProkaryotes

Section 23.2Section 23.2

Bacterial StructuresBacterial Structures

Most bacteria are composed of the Most bacteria are composed of the following parts:following parts: Outer cell wallOuter cell wall Cell membraneCell membrane

Internal foldings = thylakoids (photosynthesis)Internal foldings = thylakoids (photosynthesis) CytoplasmCytoplasm RibosomesRibosomes DNADNA Small molecules and ionsSmall molecules and ions

EndosporesEndospores

Can form in gram + bacteriaCan form in gram + bacteria Thick-coated, resistant structuresThick-coated, resistant structures Form when environmental Form when environmental

conditions are poorconditions are poor Resistant to high temp, strong Resistant to high temp, strong

chemicals, radiation, drying, etc.chemicals, radiation, drying, etc.

Prokaryotic MovementProkaryotic Movement TaxisTaxis:: movement toward or away movement toward or away

from stimulifrom stimuli ChemotaxisChemotaxis: chemical stimuli: chemical stimuli

Physical movement aided by Physical movement aided by flagellaflagella or or slimeslime

Patterns of movement: Patterns of movement: wave-like wave-like contractions or corkscrew rotationcontractions or corkscrew rotation

How do bacteria How do bacteria reproduce?reproduce?

AsexuallyAsexually via…. via…. Binary fissionBinary fission BuddingBudding

permits the permits the development of development of more complex more complex colonial structurescolonial structures Binary

fission

Buddin

g

Genetic Genetic RecombinationRecombination

ThreeThree ways that bacteria can ways that bacteria can exchange and acquire exchange and acquire new new combinations of DNAcombinations of DNA

1. 1. TransformationTransformation 2. Conjugation2. Conjugation

3. Transduction3. Transduction

1. Transformation1. Transformation

When a bacteria When a bacteria takes on DNA from takes on DNA from its its external external environment.environment. Then this new Then this new

DNA is DNA is substituted into substituted into the the bacterial DNAbacterial DNA

2. Conjugation2. Conjugation When two When two

bacterium bind bacterium bind together and one together and one bacterium bacterium transfers genetic transfers genetic information to the information to the other.other. DNA channeled DNA channeled

through the through the sex sex piluspilus

3. Transduction3. TransductionSteps:Steps:

1. Virus obtains a 1. Virus obtains a fragment of bacteria fragment of bacteria DNA from its hostDNA from its host

2. Virus multiplies 2. Virus multiplies inside host (replicating inside host (replicating the bacterial DNA as the bacterial DNA as well)well)

3. Virus breaks out of 3. Virus breaks out of host cell and invades host cell and invades new bacterianew bacteria

4. New bacterial host 4. New bacterial host will get old host’s DNA will get old host’s DNA via the virusvia the virus

Know these parts of the Know these parts of the bacteria!bacteria!

Cell WallCell Wall Outer MembraneOuter Membrane Cell MembraneCell Membrane

CytoplasmCytoplasm ChromosomeChromosome

PlasmidPlasmid Capsule & Slime LayerCapsule & Slime Layer

EndosporeEndospore PilusPilus

FlagellumFlagellum

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.

4

6

8Click above for more info!

Bacteria and Bacteria and HumansHumans

Section 23.3Section 23.3

Bacterial DiseasesBacterial Diseases

PathologyPathology – The study of diseases– The study of diseases

PathogensPathogens – anything that causes – anything that causes diseasedisease BacteriaBacteria VirusesViruses FungiFungi ProtistsProtists

Cholera attacking a cell

Bacterial PoisonsBacterial Poisons

ToxinsToxins – bacterial poisons that cause – bacterial poisons that cause diseasedisease1.1. ExotoxinsExotoxins – – made up of proteinsmade up of proteins

Secreted by the gram + bacteria to surroundingsSecreted by the gram + bacteria to surroundings Example: tetanusExample: tetanus

2.2. EndotoxinsEndotoxins – – made up of lipids and carbs.made up of lipids and carbs. Released by Released by dead dead gram – bacteria gram – bacteria Cause fever, body ache, weakness, and damage Cause fever, body ache, weakness, and damage

How to treat diseases…How to treat diseases… AntibioticsAntibiotics – fungi or – fungi or

bacteria that combat bacteria that combat infection by interfering infection by interfering with various cellular with various cellular functionsfunctions

May lead to May lead to Antibiotic Antibiotic ResistanceResistance

Caused by not Caused by not taking full dose of taking full dose of

antibioticsantibiotics

Emerging Infection Emerging Infection DiseasesDiseases

ZoonosisZoonosis:: a disease that passes a disease that passes from wild animals to humansfrom wild animals to humans Increase due to global travel of humans Increase due to global travel of humans

& destruction of natural habitat& destruction of natural habitat Example: Lyme diseaseExample: Lyme disease

Other examplesOther examples

Useful Bacteria to Useful Bacteria to HumansHumans

Probiotics- useful bacteria in your gutProbiotics- useful bacteria in your gut Recycle compounds from dead Recycle compounds from dead

organismsorganisms Create organic compoundsCreate organic compounds Food production (buttermilk, sour Food production (buttermilk, sour

cream, yogurt, cottage cheese, cream, yogurt, cottage cheese, sauerkraut, pickles)sauerkraut, pickles)

Produce fuelsProduce fuels InsecticidesInsecticides BioremdiationBioremdiation:: break down pollutants break down pollutants

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