Microorganisms, Defence Against, Etc. Flashcards
What was Pasteur’s experiment called?
The Swan-neck Experiment
How did Pasteur carry out his experiment? What did he observe and what did he conclude?
He placed sterilised broth in three flasks. One open to the surrounding air, one sealed with a bung and the third inside a swan-neck flask.
The broths were left a few weeks.
Broth in swan-neck flask and sealed flask weren’t contaminated but open flask was.
He concluded that microbes were trapped in the ‘swan-neck’ and couldn’t reach the broth but microbes could in the open flask.
What is HIV?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Virus
Exchange of bodily fluids
No cure
Minimise risk by using condoms and not sharing needles when injecting drugs
What is rubella?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Virus
Airborne- Coughing and sneezing
MMR vaccination
What is measles?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Virus
Airborne or contact
MMR vaccination
What is mumps?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Virus
Airborne
MMR vaccination
What is the cold and flu?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Virus
Airborne
Flu vaccination
What is Polio?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Virus
Drinking faeces contaminated water
Polio vaccination
What is Salmonella?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Bacterium
Contaminated food
Treated by antibiotics
Prevented by stopping cross-contamination
What is Gonorrhoea?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Bacterium
Sexual contact
Prevented by using condoms
Treated by antibiotics
What is Tuberculosis?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Bacterium
Airborne
Prevented by BCG vaccination
Treated with antibiotics
What is Chlamydia?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Bacterium sexual
Prevented by using condoms
Treated with antibiotics
What is athlete’s foot?
Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented
Fungus
Contact
Prevented by staying away from direct contact in areas where spores are likely to be present (e.g. Swimming pools)
What is the first barrier against disease in the human body? How does it stop microbes entering?
Skin
Barrier to microbes trying to gain entry
What is the second barrier against disease in the human body? How does it stop microbes entering?
Mucous membranes
Thin membranes in nose+respiratory system trap and expel microorganisms.
What is the third barrier against disease in the human body? How does it stop microbes entering?
Closes wounds quickly to prevent microorganism gaining entry
How do white blood cells fight disease?
Lymphocytes are a type of white blood cell. These produce antibodies when a microorganism enters the blood. Microorganisms have special chemicals called antigens. The antigens stimulate the lymphocytes to produce antibodies. The antibodies are complementary in shape to the antigens and latch on to them, linking them together. This immobilises the microorganisms which then allow phagocytes (another type of blood cell) to surround, engulf, digest and destroy the microorganisms.
What are the 2 types of natural immunity?
Innate-from birth mother passes antibodies across placenta.
Acquired-develops over life(catching the diseases and recovering causes the body to produce it’s own antibodies)
What are 2 types of artificial immunity?
Active-having a vaccination which causes the body to produce it’s own antibodies (as the vaccination contained a weak concentration of disease)
Passive-antibodies from another source injected into the body
Who invented the first vaccination?
Jenner in 1796
How was the first vaccination made?
Jenner noticed that milkmaid a who had suffered from cowpox didn’t catch smallpox. To experiment, in 1796 Jenner injected a small boy with cowpox. Some time after the boy had recovered from the illness, Jenner infected him with smallpox. The boy did not catch it however. The cowpox was very similar to smallpox and immunity has built up to both diseases in the boy.
What are special vaccinations and who needs them? Why is this?
They are vaccinations that are not routinely given to people in Britain.
They are given to people who travel to some foreign countries.
This is to provide antibodies against microorganisms that they have previously not encountered.
What are antibiotics?
Antibiotics are chemicals that kill bacteria or reduce their growth- they are used to combat diseases caused by bacteria.
What can some bacteria develop against antibiotics?
Resistance
What can the overuse of antibiotics lead to?
Bacteria gathering resistance
What is the name given to bacteria that are resistant to many types of antibiotics?
Superbugs
What is an example of a superbug?
MRSA
Why is it difficult to prevent/eradicate the spread of superbugs in hospitals?
Antibodies have no effect
Hospitals are an antibiotic rich environment-encouraging resistance
Many patients with open wounds and weak immune systems
Describe a typical investigation of the effect of antibiotics on bacteria in the lab.
One strain of bacteria is added to agar in a Petri dish using aseptic techniques. A multi disk containing 4 different antibiotics (A-D) is added to the Petri dish which is then incubated for a few days at 25*C
Bacteria growth was inhibited around the antibiotic B and to a lesser extent around antibiotic C. Antibiotics A and D has no effect on this strain bacteria.
What did most people believe to be how bacteria contaminated objects and what year did this change?
Most people believed in Theory of Spontaneous Generation. This was the theory that microorganisms spontaneously appeared from non-living material, until Pasteur’s experiment in 1861.
