Bacteria, Viruses, and Diseases They Cause

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Bacteria, Viruses, and Diseases They Cause
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Bacteria

• Monera kingdom was recently divided into
  Archaebacteria and Eubacteria.
• Shapes
• Bacilli rod-shaped
• Coccci sphere-shaped
• Spirilla spiral-shaped

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Bacteria - Nutrition

• Chemoheterotrophs must obtain food from organic
  molecules.
• Ex E. coli eat on good and may release toxins.
• Photoheterotrophs can obtain energy from
  sunlight, but still need organic molecules to
  feed on.
• Photoautotrophs obtain all food from sunlight.

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Bacteria Living Conditions

• Obligate aerobes require oxygen to live.
• Obligate anaerobes require the absence of oxygen
  to live.
• Facultative anaerobe can survive with or without
  oxygen.

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Bacteria Reproduction

• Binary fission most use this form of simply
  splitting in half.
• Conjugation a hollow bridge forms between 2
  bacterial cells and they transfer genetic
  material.
• Spore formation occurs when conditions are
  unfavorable and preserves DNA.

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Bacteria - Uses

• Some are decomposers.
• Help ecosystem recycle nutrients.
• Some are nitrogen-fixers.
• Convert nitrogen gas into a usable form.
• Some used in human health.
• Found in foods, drinks, and our digestive system
  to help break down food.

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Viruses

• Particles of nucleic acid, protein, and sometimes
  lipids.
• Usually composed of DNA or RNA core surrounded by
  a protein coat, called a capsid.
• They are NOT ALIVE!

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Viruses - Bacteriaphage

• Attack bacteria.

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Viruses Type of Invasion

• They are parasites because they must infect a
  living cell to grow and reproduce
• Some viruses replicate themselves immediately,
  killing the host.
• Others do not kill the host immediately.
• Lytic Infection virus enters the cell, copies
  itself, and causes the cell to burst
• Lysogenic Infection virus integrates its DNA
  into DNA of host cell, so it is replicated.

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Viruses - Retrovirus

• Contain RNA as their genetic information
• Ex AIDS

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Bacterial Diseases

• Produce disease in one of two ways.
• Some damage cells and tissues of infected
  organisms by breaking down the cell for food.
• Others release toxins that travel through the
  body of the host.
• Prevention
• Vaccine preparation of weakened or killed
  pathogen.
• Antibiotics compounds that block growth of
  bacteria.
• Controlling Bacteria
• Sterilization, disinfection, and food processing.

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Viral Diseases

• Produce diseases by disrupting equilibrium.
• Viroids often infect plants.
• Prions contain no RNA, just protein.
• Cannot be cured!