BacteriaBacteria

Chapter 18.1Chapter 18.1

Structure and FunctionStructure and Function

1. Prokaryotes microorganisms, lack nucleus, single cell

• a. Monera old kingdom

• b. divided into 2 domains: archaea and bacteria

• c. kingdoms Eubacteria and Archaebacteria

2. Cell wall different in two domains

• Eubacteria cell walls have peptidoglycan

• Archebacteria cell walls lack peptidoglycan, extreme environments, many anaerobic

MethanogensMethanogens

• Live in anaerobic Live in anaerobic environments (no oxygen)environments (no oxygen)

• Found in swamps, sewage Found in swamps, sewage treatment plants, digestive treatment plants, digestive tracts of animalstracts of animals

Extreme HalophilesExtreme Halophiles• Live in very salty Live in very salty

waterwater• Use salt to generate Use salt to generate

ATP (energy)ATP (energy)• Dead Sea, Great Dead Sea, Great

Salt Lake Salt Lake inhabitantsinhabitants

Thermoacidophiles Thermoacidophiles or Thermophilesor Thermophiles

• Live in Live in extremely extremely hothot environments environments

• Found in volcanic Found in volcanic vents, hot vents, hot springs, cracks on springs, cracks on ocean floor that ocean floor that leak acidleak acid

Kingdom Kingdom EubacteriaEubacteria

True BacteriaTrue Bacteria

CharacteristicsCharacteristics• 3 basic shapes (coccus, 3 basic shapes (coccus,

bacillus, spirilla)bacillus, spirilla)• Most are heterotrophic (can’t Most are heterotrophic (can’t

make their own food)make their own food)• May be aerobic or anaerobicMay be aerobic or anaerobic• Identified by Gram stainingIdentified by Gram staining

Shapes Are Used to ClassifyShapes Are Used to Classify

• CoccusCoccus: Spherical (round): Spherical (round)– Ex: Strep & StaphEx: Strep & Staph

• BacillusBacillus: Rod shaped: Rod shaped– Ex: E. coliEx: E. coli

• SpirillumSpirillum: Spiral shape: Spiral shape– Ex: Spirochete: wormlike spiral shapeEx: Spirochete: wormlike spiral shape

• Treponema pallidum (Syphilis)Treponema pallidum (Syphilis)

• Borelia burgdorferi (Lyme Diseae)Borelia burgdorferi (Lyme Diseae)

http://upload.wikimedia.org/wikipedia/en/3/32/EscherichiaColi_NIAID.jpg

Identified by Arrangement

• Strepto long chains• Staphlo grapelike clusters

• Diplo pairs

Diplococcus

Grape Cluster

DiplococcusDiplococcus

Streptococcus Streptococcus Causes Strep ThroatCauses Strep Throat

Staphylococcus Staphylococcus BacterialBacterial

Bacteria Can Be Identified by Gram Stains

• Gram stains dyes used to stain cells

–If pink gram negative• Thin layer of peptidoglycan• Hard to treat with antibiotics

–If violet gram positive• Thick layer of peptidoglycan• Can be treated with antibiotics

Gram Positive Gram Positive Bacteria (FYI)Bacteria (FYI)

Lactobacilli (makes Lactobacilli (makes yogurt & yogurt & buttermilk)buttermilk)

Actinomycetes (make Actinomycetes (make antibioticsantibiotics))Clostridium (Clostridium (lockjawlockjaw bacteria) bacteria)Streptococcus (Streptococcus (strep throatstrep throat))Staphylococcus (Staphylococcus (staph infections)staph infections)

Gram NegativeGram Negative• Rhizobacteria grow Rhizobacteria grow

in root nodules of in root nodules of legumes legumes (soybeans, (soybeans, peanuts)peanuts)

• Fix NFix N22 from air into from air into

usable ammoniausable ammonia

Gram NegativeGram Negative

• Rickettsiae are Rickettsiae are parasitic bacteria parasitic bacteria carried by tickscarried by ticks

• Cause Lyme disease Cause Lyme disease & Rocky Mountain & Rocky Mountain Spotted FeverSpotted Fever

Bacteria in Action

1. Decomposers– recycle nutrients

a. sewage treatment breakdown complex substances

2. Nitrogen fixation

a. bacteria grow on knobs, nodules, on roots of certain plants. Convert nitrogen gas into ammonia, a nitrogen form usable by plants

b. Nitrogen needed for amino acids, amine group NH2

Brainpop movie

• http://glencoe.mcgraw-hill.com/sites/dl/free/0078759864/164155/00044676.html

3. Diseases

a. damage tissue: tuberculosis (lungs), strept throat, Pneumonia, typhoid, cholera, tooth decay b. release toxins c. treatment: vaccines and antibiotics

– Antibiotics accidentally discovered by Fleming in 1928. A fungus, Penicilium, contaminated a bacterial culture. Fungus produces a chemical that inhibited the bacteria penicillin.

4. Commercial Uses

a. cheese, yogurt, buttermilk, sour cream, pickles, vinegar

b. digest petroleum in oil spills

c. synthesize drugs in bioengineering

Useful BacteriaUseful Bacteria• Some Some

bacteria can bacteria can degrade oildegrade oil

• Used to Used to clean up oil clean up oil spillsspills

Useful BacteriaUseful Bacteria• Other uses for Other uses for

bacteria bacteria include include making making yogurt, yogurt, cheese, and cheese, and buttermilk.buttermilk.

Making cheese, 3.5 minutes

• video\cheese, Milking_the_Cow.wmv

Making cheese, 4 minutes

• video\cheese, churning.wmv

Controlling bacteria

a. Sterilization great heat or chemicals used to destroy bacteria

b. Disinfectants a chemical solution kills bacteria; used in hospitals, homes (bathrooms and kitchens)

c. Refrigeration bacteria are slowed down

d. Canning (heat) salt, vinegar, or sugar