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Flashcards in Pathogens And Disease Deck (34):

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?

-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?

-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?


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
-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?

-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.


What do vaccines protect us from?

Bacterial and viral pathogens


What do vaccines do?

Make the person immune which prevents further infections because the body responds quickly by producing more antibodies.


What do antibodies recognise to know they need to react?

The antibodies recognise the antigen on the pathogen.


What disease can lead to long term damage to the body such as deafness and occasionally death?



Advantage and disadvantage of immunisation?

-protects society from serious diseases.
-can cause mild/serious side affects.


Process of a vaccination

-small amounts of dead/inactive pathogens are put into your body by injection
-the antigens in the vaccine stimulate your white blood cells into making antibodies, the antibodies destroy the antigens without risk of you getting the disease
- immunity to future infections by the pathogen, your body can respond quickly or make the correct antibody as if you had already had the disease


What is a pathogen?

A microorganism that causes infectious diseases


How is bacteria spread by direct contact?

Direct contact: some diseases are spread by contact of the skin, e.g. Impetigo and STDs


How does contaminated food/drink spread bacteria?

Contaminated food/drink: eating raw/undercooked food or drinking contaminated water, you take microorganism straight into your stomach. E.g. Salmonellosis


How is bacteria spread through a break in the skin?

Break in the skin: pathogens can enter your body through cuts and grazes and needle punctures, e.g. Hepatitis, HIV/Aids