1. Bacteria, Viruses & Fungi

2. Learning Intentions:  Understand features of bacteria, viruses and fungi  Understand how bacteria, viruses and fungi affect the body  Name 2 examples of bacterial, viral and fungal conditions

3. Bacteria  Prokaryotic- no true nucleus, no membrane-bound organelles  Single-celled organisms  Cell walls contain a peptidoglycan – a polymer of sugars and acids found only in bacteria that forms a mesh like layer protecting the cell membrane  Tiny - measured in units called micrometers (μm - 1 micrometer = 0.0001 cm)  Lack a true nucleus; instead, have a region called the ‘nucleoid region‘ where DNA congregates  DNA is free floating (no membrane surrounding DNA)  May have additional DNA which is not associated with this nucleoid region (called a plasmid )

4. Bacteria Characteristics…  Rapid growth and cell division (binary fission) under favorable conditions  Mutants that arise from bacteria can become extremely resilient organisms  Grow and reproduce cells quickly  Adapt quickly to changing environments  Plasmids impart additional resistant characteristics to bacteria via cell-to-cell transfer of this extra DNA material  Capable of colonizing in almost any environment

5. Bacteria

6. Bacterial Infections  Diarrhoea  Gastroenteritis  Salmonella  Tetanus  Whooping Cough  Trachoma (Eye Infection)  Q Fever  Meningococcal  Warts

7. Viruses  About 100 times smaller than bacteria – were not found until the invention of the electron microscope  Living or non-living? Just a piece of DNA  They can only grow and reproduce inside cells they have invaded – host cells!  Host cell is destroyed when it bursts open and releases new viruses that spread and infect new cells.

8. Viruses:

9. Viral Diseases  Measles  Chickenpox  AIDS  Rabies  Barmah Forest Virus  Hendra Virus  Ross River Virus

10. Antibiotics  Treat bacterial infections  Kill and prevent growth of bacteria  Selective poison which kills desired bacteria and not the cell  Different antibiotics effect bacteria in different ways which prevents their growth.  Don’t work against viruses  E.g. Penicillin

11. Fungi  Some fungi causes diseases  Often not life-threatening  Disperse using spores (single celled)  Spores need a warm, moist environment to grow  Can you think of areas around the body?  Fungal infections are contagious!  Treated with fungicide!  May occur when taking antibiotics.

12. Fungal Infections:  Tinea  Thrush