Doctors and Diseases Flashcards
What are the seven life processes?
Movement, Respiration, Sensitivity to stimuli, Growth, Reproduction, Excretion, Nutrition.
What are microbes? List some kinds of microbe.
Or micro-organisms. They are small kinds of living thing that can only be seen with a microscope. Bacteria Viruses Fungi Algae Viroids Prions
List some features of viruses.
They reproduce by viral replication.
Most scientists argue that they are not technically alive — they cannot carry out the seven life processes by themselves BUT they can if they get into a host cell.
By themselves, they move and are sensitive to stimuli.
List some features of fungi.
Not all fungi are microbes e.g. mushrooms, which have many cells.
However, yeasts, moulds, etc. are microbes.
Yeast reproduce by budding — asexual reproduction.
List some disease-causing viruses.
Influenza. Mumps. Measles. Rubella. HIV. Chickenpox. Monkeypox. COVID-19 and other coronaviruses. Poliomyelitis. Smallpox. Rabies. Viral meningitis. Roseola. Rhinoviruses. Viral tonsillitis.
Rearrange from largest to smallest size: bacterium, yeast, virus.
Yeast (avg: 3-4µm).
Bacterium (avg: 2µm).
Virus (avg: 0.02-0.03µm).
List some disease-causing bacteria.
Food-poisoning-causing bacteria. Sore-throat-causing bacteria. Tuberculosis. Tetanus. Cholera. Impetigo. Typhoid. Syphilis. Pertussis. Bacterial meningitis. Bacterial tonsillitis. Typhus. Yersinis pestis (septicæmic, bubonic and pulmonary). Lyme disease. Legionnaires’ disease [NB: not necessarily capitalised].
List some disease-causing fungi.
Athlete’s foot. Fungal sinusitis. Ringworm. Thrush. Discoloured-toe-nail-causing fungi.
What are some transmission methods for microbes?
Contaminated food/drink (e.g. food poisoning/influenza (infected glasses)).
Water (e.g. influenza/athlete’s foot).
Bodily fluids — incl. blood, sexual fluids, breast milk, saliva, vomit, urine, diarrhœa, mucus (incl. sputum/phlegm) (e.g. roseola/HIV).
Zoonotic — animal transmission (e.g. rabies).
STDs/STIs (e.g. syphilis).
Contact — direct/indirect (e.g. chickenpox).
What are the structure of bacteria, viruses and fungi?
Refer to physical flashcard.
Describe an experiment to demonstrate yeast’s optimum temperature.
5g of sugar + 3.5g of yeast + 100g in a large beaker. Add 65cm^3 of water in slowly while stirring until smooth paste.
Pour/spoon 20cm^3 (record this) into three measuring cylinders. Push stuck bits w/ stirring rod.
Label cylinders as cold (4°C), cool (20°C) and warm (45°C).
Put cylinders in different places (e.g. fridge, sitting room and oven) and leave for ~hour.
Record new volume.
4°C (24cm^3).
20°C (39cm^3).
45°C (67cm^3).
Optimum temp.: 45°C.
CO2 causes yeast to rise — to prove that yeast is necessary, simply remove it from experiment + dough will stay flat.
Dough may still not rise — too cold — no oxygen/yeast in one area — dead yeast in one area.
Dough ferments (anærobic respiration of yeast).
More sugar — a higher peak + a higher rate BUT it slows more quickly as it is quickly used up.
What are some ways to kill microbes?
Cooking (e.g. food poisoning).
Soap/antiseptics/disinfectants (e.g. typhoid/TB).
Chlorine (e.g. legionnaires’ disease).
Pasteurisation.
Salting.
Pickling (storing in ethanoic acid/brine).
Canning.
What are some ways to slow down the spread of microbes/control their population size?
These are known as mitigating/limiting factors — they slow down the R(eproduction) rate.
Freezing.
Refrigerating.
Drying.
In which conditions will microbes spread the quickest?
In their optimum conditions:
At their optimum temperatures (usually rather warm).
Amount of water (damp conditions are better).
Amount of glucose.
What are superbugs? what are some examples?
Bacteria that are resistant to antibiotics and often other forms of treatment.
MRSA (methicillin-resistant staphylococcus aureus).
C. difficile.
Why are superbugs a serious concern for hospitals? how can their spread be stopped/slowed?
If the cleaning regime is not v. strict, they will spread easily to the weakened immune systems of v. ill patients, possibly causing death. They live on bed linen, gowns, tables, floors and furniture (the order is descending in terms of likeliness). In order to stop spread: — better hygiene routine — greater control of antibiotic use — isolation
Describe an experiment involving agar that proves whether washing hands w/ or w/o soap is best to stop microbes.
Label the Petri dish with unwashed, washed w/o soap and washed w/ soap + water.
Press unwashed thumb into agar.
Repeat w/ the other two ideas. Do not dry hands.
Securely tape the Petri dish.
Wash hands again.
Turn the dish upside down and place in warm place for 48-72 hours. Observe afterwards. The best section will have the least growth.
How do our eyes protect us against disease?
Tears are antimicrobial.
Why is Louis Pasteur important in the field of microbiology?
After the first sighting of microbes in 1674, most scientists believed in ‘spontaneous generation’ — microbes just appeared.
Pasteur was the founder of microbiology.
In order to disprove s.g., he placed boiled (i.e. sterilised) broth in two kinds of flask (regular + ‘swan’ neck) and let it sit in exactly the same conditions (controlled variable).
The broth in the regular flask went off, but vice versa for the other.
He used this to show that diseases are caused by microbes in the air — ‘germ theory of disease’ — some elements are still believed today.
Pasteur invented pasteurisation for Napoleon III — rapidly increase temp., rapidly cool + seal.
How do people become naturally actively immune to disease?
They catch the disease.
The body will make and keep antibodies for the disease, but this takes a fairly long while and will usually cause a person to become ill.
Will antibiotics kill viruses? why (not)?
No — only bacteria. Viruses do not have the required structure.
Will antibiotics kill bacteria? why (not)?
Yes. Bacteria have the required structure.
How do vaccines and other artificial immunisations work?
A dead or severely weakened form of the disease is injected into the body. The body will see it as a potential threat and fight it off, but the person will not become ill because the microbe is not alive. This is so that when the actual microbe comes, the body will be able to fight it off as it will ‘remember’ the last ‘infection’.
Other forms of immunisation include:
— rubbing related diseases’ scabs on a prick (Edward Jenner)
— blowing powdered scabs up noses (ancient Chinese)
What are some advantages of vaccination?
No need to get disease + fall ill.
Endemics can only safely be stopped by vaccination.
Vaccines have a safe form of the microbe.
Vaccines are a barrier against future infection.
Herd immunity — it protects those who are unable to be vaccinated.
