Bacteria

Living Microscopic Microscopic Unicellular Earliest Prokaryotic Cells DO NOT nucleus organelles – They DO NOT contain a nucleus or membrane bound organelles The most numerous organism on Earth! Earliest bacterial fossils date back 2.5 billion years.

Most grow best at pH of 6.5 to 7.0 decomposers Many act as decomposers recycling nutrients Some are beneficial disease Some cause disease

ribosomes Contain ribosomes circular Single, circular chromosome in nucleoid region Cell Wall Cell Wall for protection Capsule May have a sticky coating called the Capsule flagella Some may have flagella for locomotion

Pili Cell Wall Chromosome Flagellum Ribosome Cytoplasm Cell Membrane

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Coccus Coccus: Spherical (round) Bacillus Bacillus: Rod shaped Spirillum Spirillum: Spiral shape

Diplo Diplo- Groups of two – Diplococcus Strepto Strepto- chains – Strephtococcus Strep throat Staphylo Staphylo- Grapelike clusters – Staphylococcus

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

Have thick layer of peptidoglycan (protein-sugar complex) Single lipid layer purple Stain purple Can be treated antibiotics with antibiotics

Thin layer of peptidoglycan in cell wall thick Extra thick layer of lipids – This keeps out more stain pinkreddish Stain pink or reddish Hard Hard to treat with antibiotics

3 There are 3 ways in which bacteria reproduce 1.Binary Fission 2.Conjugation: Sexual Reproduction 3.Spore Formation

1.Binary Fission Mitosis – Similar to Mitosis: Splitting identical – New cells are identical 2.Conjugation 2.Conjugation: Sexual Reproduction – Passing of genetic material NOT – New cells NOT identical 3.Spore Formation protectio harsh – Form endospore (hard coating) for protection when habitat conditions become harsh (little food) – Able to survive for long periods of time as endosperm – Difficult to destroy (heat resistant)

Decomposers Saprobes: Decomposers organic – feed on dead organic matter Parasites Parasites – feed on a host cell Photoautotroph sunlight – use sunlight to make food Chemoautotroph inorganic – oxidize inorganic matter such as iron or sulfur to make food

Obligate Aerobes require – require O 2 Example: tuberculosis Obligate Anaerobes present – die if O 2 is present Example: tetanus Facultative Anaerobes needkilled – don’t need O 2, but aren’t killed by it Example:

The Extremists Archaebacteria: The Extremists Found in harsh environments The True Bacteria Eubacteria: The True Bacteria Most bacteria are in this group

3 Subdivided into 3 groups: Methanogens Thermoacidophiles Extreme Halophiles

Methanogens 1. Methanogens cellulose Break down cellulose in a cow’s stomach methane Produce marsh (methane) gas

Halophiles 2. Extreme Halophiles salty Live in very salty water Use salt to generate ATP (energy) Dead Sea, Great Salt Lake inhabitants

3. Thermoacidophiles Thermophiles 3. Thermoacidophiles or Thermophiles hotacidic Live in extremely hot/acidic environments Found in volcanic vents, hot springs, cracks on ocean floor that leak acid

aerobicanaerobic May be aerobic or anaerobic Gram Identified by Gram staining Three Three types: 1.Heterotophs : include most bacteria 2.Photosynthetic Autotrophs 3.Chemosynthetic Autotrophs

1.Heterotophs 1.Heterotophs : include most bacteria organic Use organic molecules as their food source Some are parasitic Autotrophs 2.Photosynthetic Autotrophs sun Live in areas with sun; they use sun to make their food. Ex: cyanobacteria ( can be blue-green, red or yellow; commonly live in ponds) 3.Chemosynthetic 3.Chemosynthetic Autotrophs Breakdown inorganic compounds containing sulfur and nitrogen Nitrogen Fixation Nitrogen Fixation: they convert atmospheric nitrogen in to a compound that plants need to survive

metabolic waste Bacteria poison our cells with metabolic waste Your Immune system usually can not fight bacterial infections alone. Antibiotics Antibiotics can kill bacteria!

Coccus Strep Throat – Streptococcus pharyngitis (Strep Throat) – Necrotizing fasciitis (Flesh-eating Bacteria) Baccilus Anthrax – Bacillus anthracis (Anthrax) – Yersinia Pestis (Bubonic Plague) Spirillum Syphilis – Treponema pallidum (Syphilis) – Borellia burgdorferia (Lyme disease)

Alexander Flemming Discovered by Alexander Flemming – A complete accident – Mold grew in a petri dishes of bacterial cultures left in the sink – The mold killed the bacteria

degrade oil Some bacteria can degrade oil – Used to clean up oil spills

decomposers Some bacteria act as decomposers – Break down and recycle dead and decaying organic matter.

Nitrogen Fixation Some bacteria carry out Nitrogen Fixation – transform atmospheric nitrogen into fixed nitrogen, usable by plants.

Living Non-Living Genetic Material Cause Disease Can be beneficial Reproduce on their own Contain proteins Can be treated with antibiotics Many different shapes