pathogens

• Pathogen


  Microorganisms that cause infectious disease
• Types of pathogens


  • Bacteria
  • Viruses
  • Protists
  • Fungi
• Bacteria


  • Reproduce very rapidly under ideal conditions
  • Can divide every 20 minutes
  • Release harmful chemicals called toxins that damage tissues and make us feel ill
• Viruses


  • Cannot be produced by themselves
  • Can only reproduce inside a host cell
  • Invade host cell, reproduce inside, then cause the cell to burst open and die
• Ways pathogens are spread

  • Airborne (e.g. influenza)
  • Waterborne (e.g. cholera)
  • Direct contact (e.g. HIV)
• Reducing the spread of pathogens

  1. Practicing basic hygiene (e.g. handwashing)

  2. Providing clean drinking water

  3. Reducing direct contact (e.g. using condoms)

  4. Isolating highly infectious patients

  5. Vaccination
• Around 300,000 people in the UK get food poisoning from a type of bacteria every year
• Many bacterial diseases can kill us
• Viruses are very damaging to host cells, causing them to burst open and die
• foodborne illnesses are caused by bacteria, viruses, parasites, or toxins that contaminate the food supply.
• salmonella can be found on raw meat, poultry, eggs, dairy products, fruits, vegetables, nuts, spices, water, and soil.
• How do viruses reproduce? How does this make us feel ill?

  • To survive and replicate, they invade host cells (animals or plant cells).
  • The virus particle inserts its own DNA into the host cell’s DNA, which is then copied and used to make more viruses.
  • Once the new virus particles have been synthesised (made), they cause the cell to burst, releasing the new viruses to invade more cells.
  • The cell damage makes us feel ill.