Exam #1 Flashcards
What is microbiology
The study of organisms too small to be seen with the naked eye
What are prokaryotes
What are some examples
Prokaryotes have no nucleus and have less complexity
Examples:
- bacteria
- archea
What are eukaryotes
What are some examples
Eukaryotes have a nucleus and are subcellular organelles Examples: - Protozoa(parasite) - fungi - works/neliminthus -true algi
What are viruses and prions(?) ?
They are acellular
They are not a structure
They are shells of protein
They carry nucleic acid
What are the 3 domains of life
Bacteria
Archea
Eukarya
How old is the science of microbiology
Only about 150 years old
What needed to occur in order for science to be well established
1) discovery of bacteria
2) debunking of spontaneous generation
3) germ theory of disease
Who was the first person to publish established descriptions of microorganisms ?
Antony Van Leewenheok
What kind of bacteria did Antony van leeuwenheok find under the microscope
Rod Bacteria conemove Coxeyed Spirokeet Larger bacteria
Who is Luis pasteur and what did he do
He preformed Swan necked flask experiments that proved that bacteria did not spontaneously generate
He said instead bacteria that grew on an animal carcass, for example, originated from the soil, air, feces, etc.
What is the miasma theory of disease
Miasma: “bad or poisonous air” thought to cause disease
What is the germ theory of disease
Microorganisms are the cause of infectious disease
What did Robert Koch do?
He was a German physician who first linked bacteria with illness
- he linked the bacteria Bacillus Anthracis with the disease anthrax
How did Robert koch preform his experiment
1) he took an anthrax infected rodent, exposed a healthy rodent to the diseased material. The healthy rodent and he kept repeating that
2) he isolated the bacteria from the sick rodent
3) he exposed healthy rodent to anthrax bacteria and animals would get sick
3) he isolated some bacteria from experimentally infected host
Microbiology developments were also hampered by limitations in culturing then
Know this
What did Angelina hesse do
People before her would use gelatin as a solidifying but high enough temp, it would liquify
Angelina developed the use of agar as a solidifying agent
This remained solid at high temps.
What were Koch’s postulates
1) microorganisms must be present in every case of the disease
2) the organism must be grown in pure culture from the diseased animal
3) the same disease must be reproduced when a pure culture is introduced into a susceptible host
4) the organism must be recovered from experimentally infected hosts
What were the exceptions to Koch’s postulates
1) viruses cannot be cultured on standard media
2) some bacteria are difficult/impossible to grow on standard media
3) for some diseases there are asymptomatic carriers
Today we use modified Koch’s molecular postulates that focus on linking genetic material(DNA) wirh infection, instead of culturing
Know this
What were some further microbiological advances for immunity?
(3)
1) Edward Jenner - English Physician 1796: cowpox infection prevents smallpox infection (1st vaccine for smallpox)
2) Louis Pasteur: attenuated (weakened strains) used for vaccines
3) Daniel Salmon & Theobald Smith: heat killed microbes & fragments used for vaccines
What were some further microbiological advances for public hygiene ?
(5)
1) sewage disposal practices
2) hand washing
3) use of antiseptics
- ignaz semmelweis disinfects physicians hands
4) medical statistics
- Florence nightengale links infectious disease to war-related deaths
5) pasteurization
- heat food products to kill most pathogens
Who was martinis Beijernick
He discovered that mashed up filtered extract from plants infected with tobacco mosaic disease could infect healthy plants
Coined the term virus
It was not until the development of the electron microscope in the 1930’s thay the viruses were visualized
What were the reaping benefits of advancement in microbiology
Eradication
- smallpox
Reductions
- bubonic Plague
- cholera
- polio
Food production
Bioremediation
Microbial ecology
Microbiome studiesWhag are some present and future challenges from infectious disease
HIV - spillover/species jump
TB - antibiotic resistance & HIV/AID
West Nile - bird movement
Whooping Cough - vaccine change
Measles - lack of vaccination
Lyme Disease - change in animal population (deer; mouse)
Chikungunya, dengue fever, zika - global travel, climate change, mosquitoes spread
What are the options for the objective lens?
4x, 10x, 20x, 40x, 60x, 100x
What are the options for the ocular lens?
10x
The lens on a microscope is
Convex (thicker in the middle and thinner on the edges)
How does a microscope work
When light enters and leaves the lens, it refracts and bends.
Where rays of light
emerge=magnified image
How is the resolution of magnification?
The resolution is defined by the sharpness of an image
What is the resolution of the magnification influenced by
1) size of lens (bigger is better)
2) wavelength of light (shorter is better)
3) use of oil (captured more light, more info)
What is the contrast in the magnification?
The contrast = difference in light intensity
Can achieve contrast in microscopy with the use of stain
