Diseases and Pathogens

Diseases and Pathogens

1. Not all microorganisms cause disease, some are useful

   • Fungi
     • Useful as decomposers
     • Yeast
       • Yeast is used in a variety of culinary practices and to make bread, beer and wine.
   • Bacteria
     • For more about useful Bacteria: http://science.howstuffworks.com/life/cellular-microscopic/bacteria-info3.htm
     • Organic fertilizers are broken down by bacteria
     • Making Cheese
   • Viruses
     • The cowpox virus makes people immune to measles
       • For info about this click: http://microbemagic.ucc.ie/about_microbes/more_info/good_viruses.html

2. Bacteria

   • Vary in shape
   • Reproduce very quickly
     • Divide over and over again
   • Have a size of about 1/1000mm
   • Bacteria can produce poisons called toxins
     • Food poisoning is caused by this
   • Physical properties of a bacteria
     • No distinct Nucleus
     • Cell wall
     • Has cytoplasm

3. Fungi

   • They reproduce by making spores that can be carried about from person to person
   • Cause diseases like athletes foot and ringworm
   • Do not confuse fungi with mushrooms, these are very small
     • Sometimes they look like a net draped across whichever part of the inside of your body it is currently residing in.

4. Viruses

   • Viruses are on the border between the living and the non-living (dead sounds spooky)
     • They don't feed, move, respire or grow.
     • They just reproduce
   • They are much smaller than bacteria
     • They are about 1/10,000mm
   • They consist of a few genes surrounded by a protein coat
   • Viruses can only reproduce if inside another living cell
     • They release thousands of new viruses to infect new cells
     • They kill the cell they are inhabiting at the same time
   • They vary in shape

5. Fighting Disease

   • Defence Against Diseases