Eubacteria

Bacteria – Kingdom Eubacteria Oldest, most abundant and diverse group of living organisms

Characteristics Single cell Prokaryotic Single chromosome No membrane bound organelles Reproduce sexually and asexually

Structure Capsule  protect against WBC, cling to surface, protect from drying out Cell wall maintain shape Nucleoid  circular mass of DNA Plasmid  single circular DNA strand used in conjugation Pili  attachment to host cell Flagellum  motion (whip) Ribosomes  make protein

How big are bacteria?

Classification Based on Shape Arrangement Cell wall structure Carbon and energy source Oxygen requirements

Shape Spherical Rod shaped Spiral Cocci (pl) Cocus (sing) Bacilli (pl) Bacillus (sing) Spiral Spirilla (pl) Spirillum (sing)

Arrangement Prefix Diplo – twos Staphylo – cluster Strepto  chains Sarcina  octets Tetrad  fours

Cell wall structure Peptidoglycan Thin sheet composed of 2 sugar derivatives and a small group of amino acids that make up the cell wall Formation is disrupted by penicillin

Gram Positive vs. Gram Negative Thick protein layer on cell wall Stain deep purple 90% of wall is made of peptidoglycan Gram Negative Thin protein layer on cell wall 5-20% made of peptidoglycan (penicillin is not as effective) Stain pink Lipopolysaccharide layer on outside of cell wall acts as a permeability barrier

Gram Positive vs. Gram Negative

Carbon and Energy Source

Oxygen Requirements Obligate Aerobes Obligate Anaerobes require O2 for survival e.g. pneumonia, tuberculosis Obligate Anaerobes O2 not required for survival e.g. food poisoning, tetanus bacteria Facultative aerobes mainly function in the absence of oxygen; can function in the presence of O2 Facultative anaerobes grow best in presence of oxygen; can function in absence e.g. scarlet fever, typhoid fever, E. coli in human intestines

Reproduction in Bacteria Binary Fission  asexual reproduction Conjugation  sexual reproduction

Binary Fission - Video

Conjugation - Video

Bacterial Growth Exponential Growth Limited by the exhaustion of nutrients or accumulation of toxic products

Comparing Eubacteria & Archaebacteria Similarities Prokaryotic single celled No membrane bound organelles Single chromosome Reproduce asexually by binary fission

DIFFERENCES Eubacteria Cannot tolerate high temp Aerobic/anaerobic Archaebacteria Found in swamps, high salt concentration, high temp., high acidity Anaerobic (most)

How are bacteria similar to and difference from viruses? Similar  have genetic material, pathogenic (some) Different  bacteria are capable of independent life

Eubacteria and archaebacteria reproduce using binary fission.

How is this process different from mitosis? Much simpler, only single strand of DNA is replicated  no lining up along equator, spindle fibers, etc.

Explain how bacteria share genetic information Conjugation make contact with cytoplasmic bridge (pillus) Plasmids are transferred from the donor to the recipient

2. Streptomyces – source of antibiotics Describe two beneficial effects of bacteria and two harmful effects of bacteria. Include examples Beneficial: 1. Flavobacterium: dismantle complex penta molecules, leaving non-toxic CO2 + H2O and harmless chlorides. 2. Streptomyces – source of antibiotics

Harmful: legionella pneumophilia: Legionnaire’s disease 2. E.coli 157 in Walkerton

What is an antibiotic? chemicals produced synthetically or by microorganisms that inhibit the growth of or destroy certain other microorganisms

How does bacterial resistance to antibiotics develop?  genetic variation allows some to survive  pass on R (resistance) factor to next generation as well as through conjugation  R factor increases population