Bacteria

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Bacteria

description

Bacteria. Kingdom Archaebacteria. Prokaryotes Single celled Cell Wall (does not have peptidoglycan) Live in harsh environments 3 major groups 1) methanogens – swamps, digestive tracts 2) halophiles – salty areas 3) thermoacidophiles – hot & acidic areas. Kingdom Eubacteria. - PowerPoint PPT Presentation

Transcript of Bacteria

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Bacteria

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Kingdom Archaebacteria

ProkaryotesSingle celledCell Wall (does not have peptidoglycan)Live in harsh environments3 major groups

1) methanogens – swamps, digestive tracts2) halophiles – salty areas3) thermoacidophiles – hot & acidic areas

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Kingdom Eubacteria

ProkaryotesSingle celledCell wall with peptidoglycanCan live almost anywhere

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3 major bacterial shapes

1) Cocci – round2) Bacilli – rod3) Spirilli – spiral

Other terms about bacterial arrangements1) Strep = chains2) Staphylo = clusters

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Bacteria are classified according to

1) Cell wall composition (gram staining)2) Evolutionary relationship (phylogeny)3) Shape4) Motility (how they move)5) Genetics/DNA6) Metabolism (autotroph or heterotroph)

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Gram Staining

Uses 2 colored stains to determine the amount of peptidoglycan in the bacterial cell walls

Gram + = purple, peptidoglycan, penicillinGram - = red/pink, low peptidoglycan

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Helpful bacteria

• Most (about 90%) of all bacteria are harmless or helpful to us.

Can be used for:1) foods (cheese, buttermilk, yogurt, etc…)2) decomposers 3) used in industry

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Harmful bacteria

• Some bacteria can be pathogens (disease causing)

Bacterial infections & diseasesstrep throat food poisoning (botulism)gonorrhea tuberculosissalmonella lyme diseasetetanus

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What makes some bacteria harmful?1) toxins

(Exotoxins- are released by living bacteriaEndotoxins- are released when the bacteria

die)

2) the bacteria destroy tissues

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How do we treat bacterial infections?

ANTIBIOTICS – drugs that inhibit or kill bacteria

There are several types of antibiotics. Some are made from fungi or other bacteria.

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Problems caused by antibiotics

1) Antibiotic resistance2) Some people have reactions to

antibiotics

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Special structures

Capsules – some bacteria form a hard outer covering to protect them from drying out or your bodies immune system

Pili – short, ahir-like structures on the bacterial surface, used to help bacteria “stick”.

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3) Endospores – another covering that protects the bacteria from a harsh environment, allows the bacteria to go dormant.

4) Flagella – whip-like tail to help with movement

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Bacteria & reproduction

Reproduce asexually by binary fission

Reproduce sexually by conjugation (exchange genetic information between 2 bacteria)

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How bacteria get their energy

1) Heterotrophssaprophytes – decomposers

2) Autotrophsphotoautotrophs – photosynthesis

(no chloroplasts!!)

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Some bacteria need oxygen – obligate aerobes

Some bacteria die around oxygen – obligate anaerobes

Some bacteria can live with or without oxygen – facultative anaerobes

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