16-19 - Fighting Disease Flashcards
How do bacteria make you feel ill?
Producing toxins or damaging your cells
How do viruses make you feel ill?
By invading your body’s cells and replicating themselves until these cells burst and release new viruses (the cell damage causes the illness)
What do platelets do?
They cause blood to clot, closing wounds
Name some parts of your body’s “defence system”.
Skin
Hairs
Mucus
What do white blood cells do?
They fill your body in preparation to attack microbes
What are the three ways that white blood cells work?
- They engulf and digest foreign cells
- They produce antibodies
- They produce antitoxins that counteract toxins of the invading bacteria
How do antibodies work?
Produced by white blood cells
Lock onto and kill foreign antigens
Antibody production increases
Process will be faster next time pathogen is encountered
What is in a vaccine?
Dead or inactive microorganisms
Why is vaccination important?
To prevent epidemics
What is an antibiotic?
A drug which kills bacteria without killing body cells
Penicillin
Why is it difficult to create drugs that cure viruses?
Difficult to create a drug that will kill viruses without damaging your body cells
What causes bacteria to become resistant to drugs?
Mutations
How are resistant strains of bacteria prevented?
Doctors do not over-prescribe antibiotics
What does agar jelly
usually contain?
Essential carbohydrates, minerals, proteins and vitamins
How are cultures grown?
- Inoculating loops transfer microorganisms to the culture medium
- Paper discs are soaked in different antibiotics and placed on the jelly, so only resistant strains will survive
- In industrial conditions, they are incubated at high temperatures to speed growth
