Chapter 19 Bacteria & Chapter 19 Bacteria & VirusesViruses

19.1 Prokaryotes19.1 Prokaryotes

Single-celledSingle-celled Lack nucleusLack nucleus Smallest, most common microorganismSmallest, most common microorganism

ClassificationClassification

Eubacteria (D/Bacteria)Eubacteria (D/Bacteria) Larger kingdom; greater diversityLarger kingdom; greater diversity Cell wall w/peptidoglycan (carbo)Cell wall w/peptidoglycan (carbo)

E. Coli bacteria

ShapesShapes

Archaebacteria (D/Archaea)Archaebacteria (D/Archaea) Extremist (anaerobic methanogens)Extremist (anaerobic methanogens) Cell wall w/out peptidoglycanCell wall w/out peptidoglycan DNA sequence of key genes = eukaryotesDNA sequence of key genes = eukaryotes

Bacteria in hot springsBillion yr old cyanobacteria

IdentificationIdentification ShapesShapes

Bacilli: rod-shapedBacilli: rod-shaped Cocci: sphericalCocci: spherical

StreptococcusStreptococcus: chains: chains StaphylococcusStaphylococcus: clusters: clusters

Spirilla: spiral-shapedSpirilla: spiral-shaped

Streptococcus Staphylococcus

Cell WallsCell Walls Gram + : single layer; stain purpleGram + : single layer; stain purple Gram - : double layer; stain pink (disease)Gram - : double layer; stain pink (disease)

MovementMovement Flagella: whip-like structureFlagella: whip-like structure

EnergyEnergy Autotrophs (make food)Autotrophs (make food)

Photoautotrophs: cyanobacteria (aerobic)Photoautotrophs: cyanobacteria (aerobic) Chemoautotrophs: anaerobicChemoautotrophs: anaerobic

Heterotrophs (obtain food)Heterotrophs (obtain food)

Cyanobacteria

Respiration Respiration Obligate aerobesObligate aerobes: respire/need O: respire/need O22

Obligate anaerobesObligate anaerobes: ferment/killed w/ O: ferment/killed w/ O22

((C. botulinumC. botulinum))

Facultative anaerobesFacultative anaerobes: resp/ferm: resp/ferm

C. botulinum produces the potent nerve toxin that causes botulism.

Flesh eating bacteria

Tetanus

ReproductionReproduction 20 min doubling time20 min doubling time Binary FissionBinary Fission: Asexual reproduction: Asexual reproduction

DNA replicated & dividesDNA replicated & divides Identical daughter cellsIdentical daughter cells

ConjugationConjugation: Sexual reproduction: Sexual reproductionGenetic material exchange Genetic material exchange Protein bridge forms between bacteria (pilli)Protein bridge forms between bacteria (pilli)

EndosporeEndospore Internal wall enclosing DNA/cytoplasmInternal wall enclosing DNA/cytoplasmRemains dormant (months to centuries)Remains dormant (months to centuries)

19.2 Bacteria in 19.2 Bacteria in NatureNature

DecomposersDecomposers Recycle nutrientsRecycle nutrients Sewage treatmentSewage treatment

Nitrogen FixationNitrogen Fixation Fixing N2 (air) to NH3 (ammonia=fertilizr)Fixing N2 (air) to NH3 (ammonia=fertilizr) Plants need N for AA to make proteinsPlants need N for AA to make proteins

DiseaseDisease PathogensPathogens

Tissue damage: tuberculosis (lungs)Tissue damage: tuberculosis (lungs)Table 19.6 Tissue specificity as a factor in infectious disease

DiseaseTissue infected Organism

Diphtheria Throat epitheliumCorynebacterium diphtheriae

Gonorrhea Urogenital epithelium Neisseria gonorrhoeae

CholeraSmall intestine epithelium

Vibrio cholerae

Pyelonephritis Kidney medulla Proteus sp.

Dental caries Oral epitheliumStreptococcus mutans, S. sobrinus, S. sanguis, S. mitis

Spontaneous abortion (cattle)

Placenta Brucella abortus

Acquired immunodeficiency syndrome (AIDS)

T helper lymphocytesHuman immunodeficiency virus (HIV)

Malaria Blood (erythrocytes) Plasmodium sp.

 

Toxins: salmonella, tetanus, botulismToxins: salmonella, tetanus, botulism

Tetanus: permanent contraction (death by respiratory failure)

Botulism: no contraction (death by respiratory failure)

VaccinesVaccines: stimulate immune system: stimulate immune system AntibioticsAntibiotics: block growth/reproduction: block growth/reproduction

Human UsesHuman Uses Food; Industrial; Genetic engineeringFood; Industrial; Genetic engineering

Bacteria products for biological filters

BLOCKING OUT GAS. Unlike the left tower, which uses chemicals, the tower on the right at this wastewater-treatment plant now uses bacteria-covered foam blocks (inset) to eliminate the hydrogen sulfide bubbling from treated sewage.

BLOCKING OUT GAS.This wastewater-treatment towerbacteria-covered foam blocks (inset) to eliminate the hydrogen sulfide bubbling from treated sewage.

Solid waste digester takes solid organic waste and uses bacteria to turn it into methane, which is then used to generate electricity.

                                             

Daniel Bond, from the University of Massachusetts, Amherst, helped create a battery that uses common bacteria to turn organic matter from the ocean floor nto electricity. In May he will move his laboratory to the University of Minnesota, where he will work with other faculty on renewable energy.

ControllingControlling Sterilization: Sterilization: Heat; DisinfectantHeat; Disinfectant FFood: ood: Refrigerate, heat, seal, preserveRefrigerate, heat, seal, preserve

19.3 Viruses19.3 Viruses

What is it?What is it? Non-living; lack cells; need host to reproduceNon-living; lack cells; need host to reproduce Smaller/simpler than smallest cells Smaller/simpler than smallest cells DNA/RNA core; protein coat (capsid)DNA/RNA core; protein coat (capsid)

InfectionInfection Species specific (bacteriophage = only Species specific (bacteriophage = only

bacteria)bacteria)

LyticLytic: host cell destroyed: host cell destroyedVirus enters host (DNA/RNA injected)Virus enters host (DNA/RNA injected)Replicates using materials of host DNAReplicates using materials of host DNAHost burst and releases many new virusHost burst and releases many new virus

Lytic Viral Reproduction Phase

LysogenicLysogenic: uses host indefinitely: uses host indefinitelyVirus embeds DNA (prophage) into host DNAVirus embeds DNA (prophage) into host DNAReplicated w/ host DNAReplicated w/ host DNAWill eventually becomes lyticWill eventually becomes lytic

Lysogenic Phase

DiseaseDisease VaccinesVaccines: must receive before infection: must receive before infection CancerCancer: oncogenic virus: oncogenic virus

Disrupt cell growth/divisionDisrupt cell growth/division

RetrovirusRetrovirus: contain RNA: contain RNADNA copy made and inserts into host DNADNA copy made and inserts into host DNARNA to DNA (backwards)RNA to DNA (backwards)AIDSAIDS