Micro-organisms 8 Flashcards
what are the 4 types of micro-organisms and learn how to draw and label each one
1 - viruses
2 - bacteria
3 - fungi
4 - protista
describe the 4 types of micro-organisms
1 - VIRUSES
= considered non-living
= very, very small (much smaller than bacteria
? HOW do they attack their prey?
= they attack the healthy cells of the host they find themselves in. they reproduce using the material of the host cell by doing this they kill the host cell
(LEARN DIAGRAM)
? HOW do they move?
= they move in the medium / fluid they find themselves in
e.g. blood, semen, serum, water…
E.g.’s of harmful viruses
HIV, ebola, chicken pox
2 - FUNGI
= classified as living
= can be uni-cellular (1 cell = 1 organism) / multi-cellular
E.g.’s of fungi
athlete’s foot
3 - PROTISTA
= belong to the kingdom Protista
= usually uni-cellular
E.g.’s of protista
= amoeba, malaria, parasites
? HOW do they move and live?
= they live in the fluid they find themselves in. they move using flagella (tale like structures) and attach to their prey using cilia
(LEARN DIAGRAM)
4 - BACTERIA
=can be seen using microscopes even simple ones
= considered living but don’t belong to either plant / animal kingdoms. they belong to the group “Monera”
= most are uni-cellular
= they’re classified according to shape: LEARN DIAGRAMS
1 - rod shaped (bacillus) 00
2 - round shape (coccus) oo
3 - spiral (spirulli)
E.g’s of harmful bacteria
= TB, cholera, syphilis, food poisoning, tooth decay
?ARE all bacteria harmful?
= no, many are beneficial and can be used as medicine (anti-biotics)
Describe HIV
HIV - human immuno-deficiency virus
Aids - aquired immuno-deficiency syndrome
immuno
= immunity
=has to do with your immune system
- protects the body from harmful micro-organisms
- the main cells of the immune system are white blood cells
deficiency
= lacking something
= doesn’t work well
?WHAT CAUSES AIDS?
?HOW does the virus enter the body?
- through contact with body fluids of and infected person. this contact includes sexual contact, sharing needles, contact with infected blood, transfer from mother to child during pregnancy, breastfeeding
?HOW do we cure it?
- no cure, for both HIV and Aids, however we can manage the disease. this is done by adopting a healthy lifestyle and keeping track of anti-retroviral meds (ARV).
if your CD4 (T helper cell) cell count crops too low you have to start ARV treatment in order to raise the CD4 level
?WHAT does the HIV do once inside the body?
- the virus infects the cells of the immune system and kills them, they no longer protect your body and you are now exposed to other micro-organisms, e.g. TB
Signs of symptoms of HIV / Aids
- initially the patient presents with a sore throat, swollen glands, aching muscles and joints. these symptoms disappear and you then feel better, you (your patient) then could remain asymptomatic for as many as 10 years. during these 10 years the virus load is increasing and destroying your immune cells when your CD4 cell count is below 200 you have Aids.
describe malaria
(LEARN DIAGRAM)
?WHAT causes malaria?
- and infection with the plasmodium parasite
?HOW do we contract malaria?
- the anopheles female mosquito carries the parasite and bites a human host. the parasite now leaves the mosquito and enters the blood of the host. the parasite enters / travels to the liver and multiplies and infects red blood cells. Inside the RBC the parasite multiplies and when mature enough erupts out of the RBC, destroying it
Signs and symptoms of malaria
- high fever, chills, weakness, sweating, headache, vomiting
Treatment and prevention
1 - use mosquito repellents
2 - avoid areas where the anopheles lives
3 - take prophylactics which kill the parasite in the blood
describe TB
- kills about 3 million a years
- can attack any part of the body but usually the lungs
- spread through the air
- symptoms = a bad cough that lasts longer than 2 weeks, chest pain and coughing up blood. always tired, suffer from headaches, may lose weight and get chills and fevers
- skin test and X-rays show if someone has TB
- there are 4 effective antibiotics against TB
- to prevent antibiotic resistance, person must take medicine for 6 months
the relationship between TB and HIV
- HIV positive people have a greater chance of contracting TB
- although TB in HIV infected people can be cured of prevented many still die
- 2010 496 500 people living with TB and 25 000 deaths in SA
describe water born diseases
- caused by drinking infected water with micro-organisms
- most water born diseases cause vomiting and severe diarrhoea
water born diseases can be caused by protozoa, protista and bacteria - diarrhoea can lead to death if accompanied by vomiting and this is because of severe dehydration
describe cholera
cholera = vibrio cholerae -> name of organism causing cholera
?WHERE is it found?
- it’s a bacterium found in the intestines
?HOW does it spread?
- water born disease spread by the housefly (musca domesticata). you drink / eat food infected with the bacterium and it enters your body
?WHY do we get sick after cholera infection?
- the bacterium releases toxins which travel into small intestines and cause the release of water (diarrhoea)
(LEARN DIAGRAM)
describe e.coli
Full name = Eschericia coli
- found in the lower digestive system (which is the small and large intestines)
- if the bacterium is eaten either through infected food / water, it travels to your stomach where it causes your cells to release water (resulting in diarrhoea / vomiting)
- in the lower digestive system the E. coli bacterium isn’t harmful it is helpful, it helps digest our food
describe useful micro-organisms (decomposers and medicine and food)
(LEARN DIAGRAM)
?What are some e.g’s of useful micro-organisms?
- decomposers, bacteria, fungi and protista are useful micro-organisms. we use them to help with nutrient recycling as well as for making medicines and some foods. some of the useful food groups which we use micro-organisms for are for making beer / yoghurt
DECOMPOSERS
= organisms which break down dead mater. decomposers that we know of are fungi, protists and bacteria
?WHY do we have decomposers?
in order to return the nutrients from the dead animals to the soil and for nutrient recycling
Using micro-organisms as medicine
- Sir Alexander Fleming discovered penecillin (the medicine) in 1881. he worked with bacterial cultures and found that a fungus grew that killed bacteria. this fungus was penicillum, the product that today we get the antibiotic, penecillin
Antibiotics are used for
- killing bacteria, protists, parasites and for stopping infections
Using micro-organisms to make food
- micro-organisms have been used for many years as they are used for making beer, wine, cheese, bread etc.
- micro-organisms are used to ripen and mature cheese
- yoghurt was discovered in Turkey where milk was added to bacteria allowing milk to become partially digested and partially fermented, thereby forming yoghurt
what are the 5 steps to determining micro-organisms size
1 - measure the length of the scale bar (cm / mm)
2 - measure the length of the micro-organisms (cm / mm)
3 - divide the length of the micro-organisms by the length of the scale bar
4 - multiply the number above the scale bar by the answer of step 3
5 convert the answer to μm by dividing your answer by 1000
