Introduction and History of Microbiology - Chapter 1` Flashcards
What does microbiology encompass?
Virology, bacteriology, protistology, mycology, immunology, and parasitology
What is microbiology?
Study of microorganisms, those being unicellular, multicellular, or acellular
Unicellular
Single-cell
Multicellular
Cell colony
Acellular
Lacking cells
What are examples of acellular things?
Prions and viruses
Virology
Study of viruses
Bacteriology
Study of bacteria
Protistology
Study of protists
Protists
Unicellular, eukaryotic microbes
Mycology
Study of fungi
Immunology
How our body handles microbes
Parasitology
Covers eukaryotic pathogens
What is included in parasitology?
Protists and helminths
What are the domains of life?
Bacteria, archaea, and eukarya
Bacteria Microbes
All are microbes
Archaea Microbes
All are microbes
Eukarya Microbes
Some are microbes
Are all microbes in the tree of life?
No, some are viruses or prions
Viruses
Acellular, noncellular organisms, no domain
Prions
Infectious proteins
Prokaryote Domains
Bacteria and archaea
Eukaryotes Domains
Eukarya
Prokaryote Classification
Unicellar, lack a nucleus, and must have a cell wall
Eukaryote Classification
Unicellular or multicellular, contain a nucleus, and have membrane-bound organelles
What are the types of eukaryotes?
Fungi, algae, protozoa, and helminths
Fungi
Unicellular or multicellular, can be yeast, NOT mushrooms
Helminths
Worms, they are often spread in larval form (microscopic)
Do all microbes cause infectious diseases?
No, not all microbes cause infectious diseases
Size of microbes
They are very small ranging from 0.1nm to 1mm
What microscope will we use to observe microbes?
We will be using a light microscope, but an electron microscope can also be used
Spontaneous Generation
The idea that life arises from non-living matter
What are the observations that led to spontaneous generation?
-Where there is dust fleas arise
-Where there is rotting meat there are maggots
-Where there is flooding frogs appear
-In grain storage areas mice appear
What observation was Francesco Redi’s experiment based on?
The idea of where there are meats there are maggots
Francesco Redi’s Experiment
There were 3 experimental conditions:
-Meat in an open container
-Meat in a cork-sealed container
-Meal in a gauze-sealed container
What happened to the meat in the open container?
Flies appeared and maggots formed
What happened to the meat in the cork-sealed container?
No flies or formation of maggots as they couldn’t smell the meat
What happened to the meat in the gauze-sealed container?
Flies appeared and there was no formation of maggots on the meat, but rather the formation of maggots on the gauze
What was the conclusion of Francesco Redi’s Experiment?
Maggots come from flies and are not spontaneously generated.
Refutes spontaneous generation.
Needham’s Experiment
Was a boiling broth experiment where a container with chicken broth was heated to kill microbes then sealed and later looked at. There was a growth in the broth.
Needham’s Experiment Conclusion
Supported spontaneous generation
Spallanzani’s Experiment
He had 2 flasks, 1 was left sealed and 1 was left open
What happened to the sealed flask in Spallanzani’s Experiment?
There was no growth until it was later opened
What happened to the open flask in Spallanzani’s Experiment?
There was growth
Spallanzani’s Experiment Conclusion
Whatever is growing comes from the air, refutes spontaneous generation
What was the difference between Needham’s and Spallanzani’s Experiments?
In Needham’s Experiment, the broth was clear and may still have contained microbes
Louis Pasteur’s Experiment
Used 2 swan neck flasks and boiled both of them, he left 1 the same and took the neck off of the other
What happened to the normal swan neck flask?
There was no growth
What happened to the swan neck flask whose neck was removed?
There was growth
Louis Pasteur’s Experiment Conclusion
Particles in the air cause contamination, disproved spontaneous generation
Swan Neck Flask
Contains bins where air can move freely and particles in the air get stuck in the neck so that they are not in the solution.
Anthony van Leewenhoek
First-person credited with visualizing microbes
What did Anthony van Leeuwenhoek look at in the microscope?
Either rain or pond water
What did Anthony van Leeuwenhoek see in the water?
He saw single-celled eukaryotes and drew them which he called “wee animalcules” at the time
Cell Theory
Living things are made of cells
Cells divided to make new cells
Robert Hooke
The first person to observe cells when looking and cork.
He coined the term “cell”.
Matthias Schleiden
Observed cells in plant tissue
Theodor Schwann
Observed cells in animal tissues
Rudolf Virchow and Robert Remark
Discovered that cells divide to make new cells
Walter Fleming
Showed mitosis occurred
What was the previous notion of the cause of disease?
The God/Gods were punishing people when they did bad things
Hippocrates
Believed disease had a natural cause
Hippocratic Oath
Oath to do no harm
Thucydides
Advocated for evidence-based analysis of cause and effect.
Immunity -> Noticed that plague survivors don’t get sick by the plague again
Marcus Terentius Varro
First to propose we can’t see what causes disease
Cytoreductive
Killing Cells
What bacteria produces a green pigment and is found in the lungs?
Pseudomonas aeruginosa
What is Pseudomonas aeruginosa often associated with?
Cystic fibrosis and extreme mucus production
Who are the people that have proved that microbes cause disease?
Ignaz Semmelweis, Joseph Lister, Robert Koch, and John Snow
What did Ignaz Semmelweis notice?
When treating patients, patients would get another disease that another patient had at the hospital
What did Ignaz Semmelweis institute?
Workers had to wash their hands between seeing patients
What did Ignaz Semmelweis notice after he implemented his change?
He noticed a lack of spread of disease proving that healthcare workers were the ones transferring disease.
What did Joseph Lister notice?
Post-surgical infections
What did Joseph Lister implement?
Hand washing and cleaning the surgical in a 5% phenol solution
What was the result of Joseph Lister’s implementation?
Decrease in post-surgical infections
What did Robert Koch determine?
Determined the rules for how we determine which microbe causes which disease
Who is the father of epidemiology?
John Snow
What did John Snow notice?
Noticed that there was a cholera outbreak and that certain groups of people that kept getting it.
What did John Snow discover?
Discovered that there were 2 water pumps that everyone drank from and that the people at the brewery did not get sick as they weren’t drinking water.
Cholera
Found in contaminated water and causes diarrhea
Endosymbiotic Theory
How we have eukaryotic cells. Uptake of bacteria led to the formation of mitochondria and chloroplasts.
Where do eukaryotic cells come from?
Prokaryotic cells that came together to form a eukaryotic cell
Proto-eukaryote
A prokaryote that will turn into a eukaryote
What is the first step of the endosymbiotic theory?
Invagination of membranes and the start of the formation of membrane-bound organelles (ER, nuclear membrane, etc.)
What is the second step of the endosymbiotic theory?
Cells take up aerobic bacteria
What does an aerobic bacteria do?
Oxygenic cellular respiration
What does aerobic bacteria develop into?
Mitochondria
What is the third step of the endosymbiotic theory?
Some cells, not all, will take up a photosynthetic bacterium
What does a photosynthetic bacterium do?
Photosynthesis
What do photosynthetic bacterium develop into?
Chloroplasts
What did the uptake of bacteria lead to?
It led to the formation of mitochondria and chloroplasts
What is some evidence of the endosymbiotic theory?
Mitochondria have their own DNA and mitochondria and chloroplasts have their own ribosomes which are the same size as prokaryotes
Do all cells that have chloroplasts have mitochondria?
Yes
Do all cells that have mitochondria have chloroplasts?
No, as mitochondria develop first
Where can you find a prokaryotic ribosome in a eukaryotic cell?
Mitochondria or chloroplasts
Taxonomy
Classification of organisms, phylogenetic tree, tree of life
Where are microbes found in the phylogenetic tree?
They are in every category
Nomenclature Rules
Have to be in italics, the first word is capitalized and the second word is lowercased, Genus species
Genus spp
Multiple species in a genus with similar properties
Genus sp
An unknown or unnecessary species
What are some types of microbes?
Bacteria, archeae, fungi, protists, and viruses
Who first visualized microbes and called them “wee animalcules”?
Antony von Leuwenhoek
How was spontaneous generation definitively disproved?
Louis Pasteur used swan neck flasks to disprove this
