Pathogens And Disease Flashcards
(34 cards)
What do bacteria do inside our bodies?
- reproduce rapidly
- produce toxins that make us feel ill
What do viruses do inside cells?
How big are viruses?
- reproduce
- damage cell
- destroy cell
-viruses are much smaller
What is an epidemic?
When a wide spread of people have a disease
What is a pandemic?
When the disease affects a whole country or goes world wide, e.g. Swine flu
What did Semmelweis prove?
- 1840s
- death rates of women
- doctors transferred diseases because of not washing their hands
What is the droplet infection?
Droplet infection: when you cough or sneeze tiny droplets are released in the air and breathed in by other people. E.g. Flu
What is the first line of defence?
Explain
Skin: acts as a barrier to prevent pathogens getting into the body. If the skin gets broken, the platelets in the blood form a clot which dries into a scan, seals cut.
Breathing system: produces sticky mucus that traps pathogens. It is then moved out of the body or into the stomach where it’s destroyed by stomach acid
What is the second line of defence?
The white blood cells: these destroy the pathogens in a number of ways.
- Ingesting microorganisms, ingest(take in) pathogens and destroy
- Producing antibodies, target particular bacteria/viruses and destroy
- Producing antitoxins, these cancel out the poisons released by pathogens
What are antibiotics?
Antibiotics will kill infective bacteria in the body. They damage the bacterial cells without harming their own.
Can antibiotics be used to treat viruses and why?
Can’t be used to treat viruses because viruses reproduce inside the body cells so the treatment would damage the cells
What do drugs like paracetamol do and how do they treat?
They are symptom relievers- can’t treat bacteria
Who first discovered Penicillin and when?
- Alexander Fleming
- 1928
- wanted something to kill bacteria, noticed the effect of mould on his cultures, then developed by Ernst Chain and Howard Floret dk it could be produced on an industrial scale
Where can’t antiseptics and disinfectants be used and what do they do?
Can’t be used to kill bacteria inside body as too poisonous for inside body
What can pure cultures of non-pathogenic(safe) bacteria be used for?
Can be used in a lab for laboratory investigations
What can a culture of microorganisms be used to find?
A culture of microorganism can be used to find the effect of antibiotics on bacteria
What do cultures (bacteria) need to be to protect people and why?
- uncontaminated
- if not uncontaminated other bacteria could grow, including pathogens
What nutrients do culture microorganisms need to grow?
They need a culture medium called Agar Jelly, this contains the nutrients needed for growth.
Where should culture microorganisms be kept and at what temperature?
-incubated at 25 degrees in school labs and 35degrees in industry. They need oxygen.
What do you have to do to keep the culture pure?
-pass metal loops through a flame, boil solutions and agar. Also prevent microorganisms getting in from the air.
What can some pathogens, particularly viruses, do to cause new strains which can lead to epidemics or pandemics?
-mutate forming a mutation, survive and reproduce.
What is antibiotic resistant bacteria?
Bacteria that have evolved though natural selection. E.g. MRSA
Why should antibiotics not be used too often?
To slow down the rate of resistant strains developing.
What is used to make a vaccines
Dead or inactive forms of a pathogen.
How is a vaccine given?
It can be inherited into the body.
