1 Bacteria Structure and Function

2 Prokaryote & Eukaryote Evolution

3 Cellular Evolution Current evidence indicates that eukaryotes evolved from prokaryotes between 1 and 1.5 billion years ago

4 Prokaryotic & Eukaryotic Cells

5 Earliest Prokaryotes Most numerousMost numerous organisms on Earth bacteriaInclude all bacteria Earliest fossils dateEarliest fossils date 2.5 billion years old

6 Classification of Life

7 Three Domains of Life Archaea – prokaryotes living in extreme habitatsArchaea – prokaryotes living in extreme habitats Bacteria - Cyanobacteria and eubacteria Bacteria - Cyanobacteria and eubacteria Eukarya – Protozoans, fungi, plants, & animals Eukarya – Protozoans, fungi, plants, & animals

8 Kingdoms of Bacteria Archaebacteria: Found in harsh environments Found in harsh environments Undersea volcanic vents, acidic hot springs, salty water Undersea volcanic vents, acidic hot springs, salty water

9 Archaebacteria

10 Kingdoms of Bacteria Eubacteria: Called the true bacteria Called the true bacteria Most bacteria are in this group Most bacteria are in this group

11 Eubacteria

12 Characteristics of Bacteria

13 Bacterial Structure Microscopic prokaryotesMicroscopic prokaryotes No nucleus or membrane- bound organellesNo nucleus or membrane- bound organelles

14 Bacterial Cell

15 Sticky Bacterial Capsule

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17 Bacterial Structure Most grow best at pH of 6.5 to 7.0Most grow best at pH of 6.5 to 7.0 Many act as decomposers recycling nutrientsMany act as decomposers recycling nutrients Some cause diseaseSome cause disease

18 Staphylococcus Bacterial

19 Useful Bacteria Some bacteria can degrade oilSome bacteria can degrade oil Used to clean up oil spillsUsed to clean up oil spills

20 Useful Bacteria Other uses for bacteria include making yogurt, cheese, and buttermilk.Other uses for bacteria include making yogurt, cheese, and buttermilk.

21 Flagella Bacteria that are motile have appendages called flagellaBacteria that are motile have appendages called flagella Attached by Basal BodyAttached by Basal Body A bacteria can have one or many flagellaA bacteria can have one or many flagella

22 Pili Short protein appendagesShort protein appendages Smaller than flagellaSmaller than flagella Adhere bacteria to surfacesAdhere bacteria to surfaces Used in conjugation for Exchange of genetic informationUsed in conjugation for Exchange of genetic information Aid Flotation by increasing buoyancyAid Flotation by increasing buoyancy

23 Pili in Conjugation

24 Bacterial Shapes

25 Shapes Are Used to Classify Bacillus: Rod shapedBacillus: Rod shaped Coccus: Spherical (round)Coccus: Spherical (round) Vibrio: Comma shaped with flagellaVibrio: Comma shaped with flagella Spirillum: Spiral shapeSpirillum: Spiral shape Spirochete: wormlike spiral shapeSpirochete: wormlike spiral shape

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27 Grouping of Bacteria Diplo- Groups of twoDiplo- Groups of two Strepto- chainsStrepto- chains Staphylo- Grapelike clustersStaphylo- Grapelike clusters

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29

30 Diplococcus

31 Streptococcus Causes Strep Throat

32 Staphylococcus

33 Bacillus - E. coli

34 Streptobacilli

35 Spirillum

36 Spirochetes

37 Leptospira

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39 Gram Staining Developed in 1884 by Hans GramDeveloped in 1884 by Hans Gram Bacteria treated with purple Crystal Violet & red Safranin stainsBacteria treated with purple Crystal Violet & red Safranin stains Cell walls either stain purple or reddish pinkCell walls either stain purple or reddish pink

40 Gram Positive Have thick layer of peptidoglycan (protein-sugar complex)Have thick layer of peptidoglycan (protein-sugar complex) Single lipid layerSingle lipid layer Stain purpleStain purple Can be treated with antibioticsCan be treated with antibiotics

41 Gram Positive Bacteria Lactobacilli (makes yogurt & buttermilk) Lactobacilli (makes yogurt & buttermilk) Actinomycetes (make antibiotics) Actinomycetes (make antibiotics) Clostridium (lockjaw bacteria) Clostridium (lockjaw bacteria) Streptococcus (strep throat) Streptococcus (strep throat) Staphylococcus (staph infections) Staphylococcus (staph infections)

42 Gram Negative Bacteria Thin layer of peptidoglycan in cell wallThin layer of peptidoglycan in cell wall Extra thick layer of lipidsExtra thick layer of lipids Stain pink or reddishStain pink or reddish Hard to treat with antibioticsHard to treat with antibiotics Some photosynthetic but make sulfur not oxygenSome photosynthetic but make sulfur not oxygen Some fix nitrogen for plantsSome fix nitrogen for plants

43 Gram Negative Rhizobacteria grow in root nodules of legumes (soybeans, peanuts)Rhizobacteria grow in root nodules of legumes (soybeans, peanuts) Fix N 2 from air into usable ammoniaFix N 2 from air into usable ammonia

44 Gram Negative Rickettsiae are parasitic bacteria carried by ticksRickettsiae are parasitic bacteria carried by ticks Cause Lyme disease & Rocky Mountain Spotted FeverCause Lyme disease & Rocky Mountain Spotted Fever

45 Nutrition, Respiration, and Reproduction

46 Modes of Nutrition Saprobes – feed on dead organic matterSaprobes – feed on dead organic matter Parasites – feed on a host cellParasites – feed on a host cell Photoautotroph – use sunlight to make foodPhotoautotroph – use sunlight to make food Chemoautotroph – oxidize inorganic matter such as iron or sulfur to make foodChemoautotroph – oxidize inorganic matter such as iron or sulfur to make food

47 Methods of Respiration Obligate Aerobes – require O 2 (tuberculosis bacteria)Obligate Aerobes – require O 2 (tuberculosis bacteria) Obligate Anaerobes – die if O 2 is present (tetanus)Obligate Anaerobes – die if O 2 is present (tetanus) Facultative Anaerobes – don’t need O 2, but aren’t killed by it (E. coli)Facultative Anaerobes – don’t need O 2, but aren’t killed by it (E. coli)

48 Bacterial Respiration Anaerobes carry on fermentationAnaerobes carry on fermentation Aerobes carry on cellular respirationAerobes carry on cellular respiration

49 Reproduction Bacteria reproduce asexually by binary fissionBacteria reproduce asexually by binary fission Single chromosome replicates & then cell dividesSingle chromosome replicates & then cell divides RapidRapid All new cells identical (clones)All new cells identical (clones)

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

51 Binary Fission E. coli

52 Reproduction Bacteria reproduce sexually by ConjugationBacteria reproduce sexually by Conjugation Form a tube between 2 bacteria to exchange genetic materialForm a tube between 2 bacteria to exchange genetic material Held together by piliHeld together by pili New cells NOT identicalNew cells NOT identical

53 Conjugation

54 Spore Formation Form endospore whenever when habitat conditions become harsh (little food)Form endospore whenever when habitat conditions become harsh (little food) Able to survive for long periods of time as endospermAble to survive for long periods of time as endosperm Difficult to destroy (heat resistant)Difficult to destroy (heat resistant)

55 Transduction & Transformation Genetically change bacteriaGenetically change bacteria May become antibiotic resistantMay become antibiotic resistant Transformed bacteria pick up pieces of DNA from dead bacterial cellsTransformed bacteria pick up pieces of DNA from dead bacterial cells Transduction – viruses carry foreign DNA to bacteria; used to make insulinTransduction – viruses carry foreign DNA to bacteria; used to make insulin

56 Pathenogenic Bacteria

57 Pathogens Called germs or microbesCalled germs or microbes Cause diseaseCause disease May produce poisons or toxinsMay produce poisons or toxins Endotoxins released after bacteria die (E. coli)Endotoxins released after bacteria die (E. coli) Exotoxins released by Gram + bacteria (C. tetani)Exotoxins released by Gram + bacteria (C. tetani)