BACTERIA

Domain Bacteria, Domain Archea, Used to be combined under Kingdom Monera * cell type * Heterotrophic or Autotrophic Kingdom Eubacteria (true) Kingdom Archaebacteria (ancient) Prokaryotic

Recall that the archaea are more closely related to the eukaryotes, while the bacteria are related to cell organelles such as mitochondria and chloroplasts. Kingdom Eubacteria Kingdom Archaebacteria PROKARYOTES

How do we know that those little bitty things under the microscope aren’t all the same “stuff”? How do we know that the Archaea are more closely related to the Eukarya?

Recall Prokaryotic Vs. Eukaryotic Prokaryotes DO NOT have: –Nucleus –Membrane-bound organelles Prokaryotes DO have: –DNA (all) –Ribosomes (all) –Cell membrane (all) –Cytoplasm/Cytoskeleton (all) –Cell Wall (many) –Flagella (some) –Capsule (many) –Pili (some) Ex. bacteria Eukaryotes DO have: –Nucleus –Membrane-bound organelles (such as mitochondria, ER, golgi, etc.) –DNA (inside nucleus) –Ribosomes –Cell membrane –Cytoplasm/Cytoskeleton –Cell Wall (some) –Flagella (a few) Ex. Animals, Plants, Fungi, Protists

Eubacteria Diagram Good web-site to look at eubacteria cell structure:

Pili on a bacillus bacterium Pili are used by a bacterium to attach to surfaces and for sexual reproduction.

CHARACTERISTICS of Bacteria: 1. Most reproduce asexually through binary fission. ( Dividing in half; identical offspring) 2. Some reproduce sexually by conjugation connecting at their pili. (cell to cell contact; new combination of genes)—Pili are also used to attach to surfaces 3. Classified by cell shape, cell wall, respiration, and nutrition.

Characteristics of Bacteria continued 4. Can be Gram + or Gram - 5. Some may form endospores 6. Toxins – chemicals produced by bacteria that are poisonous to eukaryotic cells and cause disease

Rod-shaped bacteria dividing by binary fission 1. Asexual reproduction

Conjugation in Bacteria 2. Sexual reproduction

3. Bacterial Shapes coccusspirillum bacillus

3. Three different shapes: 1. Coccus (spheres): 2. Bacillus (rods): 3. Spirillum (spirals): Two different arrangements: Strepto (chains) Staphylo (clusters) What would diplo be?

Archaebacteria: “ancient”  Autotrophic  Cell walls with NO peptidoglycan  found in harsh environments 1. Methanogens- no oxygen, make methane gas 2. Thermophiles- very hot water 3. Halophiles- very salty conditions, 10x saltier than ocean water

Archaea in San Francisco Bay area – extremely high salinity. What kind of archaea are these? halophiles

EUBACTERIA “true” Largest and most diverse of the bacterial kingdoms Found everywhere Most are heterotrophic Cell walls are present with peptidoglycan Many have flagella that aid in movement

3. Nutrition Types AUTOTROPHS –Photosynthetic—use pigments to capture light energy to convert to chemical energy ex. cyanobacteria –Chemosynthetic—use inorganic molecules or organic molecules to make amino acids  proteins; live in soil and nitrify ammonia ex. sulfur bacteria & methanogens; nitrifying bacteria (Nitrobacter spp.) HETEROTROPHS –Principal decomposers (along with fungi) –Many produce antibiotics (ex. Streptomyces) –Some fix nitrogen (ex. Rhizobium)

Cyanobacteria

4. Comparison Gram + & Gram - Eubacteria Color PurpleRed Amount of peptidoglycan MoreLess Toxicity LessMore Antibiotic effective against? Most of the time Not always FeatureGram +Gram -

Gram + Gram – (the lipid layer on the outside makes it hard for antibiotics to work on G-) Peptidoglycan – the tan rods in the diagram; lots in Gram +, little in Gram -

5. ENDOSPORES Thick wall Resistant to heat, dryness, etc May survive for years in harsh conditions When conditions are favorable, the bacteria will grow from the spore Example: Anthrax; Clostridium botulinum (causes Botulism—a form of food poisoning)

6. Diseases caused by Bacteria: * Tuberculosis * Anthrax * Lyme disease * E. coli * Bubonic plague *Typhoid fever*Cholera *Strep throat*Dental cavities *diphtheria*pneumonia *Salmonella

Yellow bacillus bacteria in the lining of the human nose. This species causes pneumonia.

Beneficial Beneficial Bacteria: There are some bacteria you’ve just got to love! *Decomposers and Nitrogen fixers *Bacteria is used to make certain foods like cheese and yogurt. * To manufacture plastics and many pharmaceuticals. * Digests cellulose in animals * Sewage treatment plants * Medicines like insulin

Develop Mutualistic relationships with other organisms: Ex. the fish provides the bioluminescent bacteria under its eye with organic materials, the fish uses its living flashlight to lure prey and to signal potential mates.

Questions to Ponder Why are bacteria important organisms in the ecosystem? In what ways are bacterial beneficial to us? Explain. Describe bacterial diseases including cause, symptoms, and transmission. What are the shapes and arrangements of bacteria and how can these be used in classification?