Microbiology Discovery Flashcards
Leeuwenhoek’s microscope was ____ times stronger than Hooke’s
250
The rise of microscopes conflicted with the theories and how life _______
emerged
Miasma comes from the Greek word _______
pollution
We evolved to dislike the smell of bad _______ to stay safe
bacteria
Cholera is like the opposite of _______ _______ for the chloride channel. What happens in the body?
Cystic fibrosis
When a cell ingests cholera toxin, the CFTR chloride channel proteins becomes phosphorylated and open, allowing water, Na, and K into the intestinal lumen. This results in rapid fluid loss.
What is microbiology?
The study of minute life forms
What is a micro-organims/microbe?
Any living thing that can only been see though a microscope
What are the 7 types of micro-organisms?
bacteria Archaea protozoa algae fungi viruses (even though they're not alive) multicellular animal parasites
When was the existence if microbes demonstrated and by who?
1665 - Robert Hooke discovered microscopic fungi with his compound microscope
1676 - Antonie van Leeuwenhoek designed a single lens microscope that could see bacteria and other microbes
Ferdinand Cohn classified bacteria into what four groups?
Spherical
short rods
straight filaments
spiral filaments
What is spontaneous generation? Up until which century was this the prevailing belief?
The idea the living creatures could arise from non-living matter without descent from similar organisms
19th century
What are some examples of spontaneous generation?
Fleas could arise from dust
Maggots could arise from dead flesh
Who was the earliest scholars to propose that life can arise from non-living material if it contained pneuma (vital heat)
Aristotle
Why did Thucydides think diseases could spread from an infected person to another?
He witnessed the plague of Athens. One theory is that the disease was spread by spore like “seeds”/semina
Which roman statesman advised to be careful in the swamps because of minute creatures that can cause serious diseases if they entered the mouth and nose
Marcus Terentius Varro
What is Miasma Theory? When was it popular?
Diseases were caused by a miasma (a noxious form of bad air) emanating from rotting organic matter
Popular in ancient times in Europe and China
In Miasma Theory, infections are not passed between __________, but rather would affect those within the poisonous vapor
individuals
Some people tried to extend miasma theory for other conditions. What is an example?
Inhaling food odor could make one obese
When and what was Miasma Theory replaced with?
Replaced in 1880 with germ theory
What is germ thoery?
- It states microbes known as pathogens or germs can lead to disease.
- They invade living hosts and cause disease due to their growth and reproductions
- Germ refers to not just bacterium, but any microbe such as protists, fungi, viruses, prions, or viroids
- Diseases caused by pathogens are called infectious diseases
In 1665, How did Francesco Redi demonstrate that maggots do not spontaneously generate on meat?
He left meat in an:
- Open container (maggot on meat)
- Sealed container (no maggots)
- Container covered with gauze (maggot on gauze)
He concluded maggots are the offspring of flies
What was John Snow’s contribution to work on Cholera?
1849 - Suggested fecal-oral route was mode of communication for cholera. Recommended that water be filtered and boiled before it is used
1854 - Found link between cholera and sewage contaminated water. He used dot map of London and statistics to find the link of the water source.
From the on, developed countries invested in clean water supplies
Who is the Father of Epidemiology?
John Snow
When and who isolated the cholera bacterium Vibro Cholerae. Did anything come of this?
1854 - Philippo Paccini
Nothing came of this, as he did not know it caused cholera
What is the scientific method?
- Form hypothesis
- Define independent variables and make a control and experimental group
- Determine what you will analyze for the dependent variables
- Predict your results and then perform the experiment. Is your hypothesis correct?
What year did Louis Pasteur definitively refute the theory of spontaneous generation?
1858
What was Louis Pasteur’s first experiment. Why was it refuted?
Boiled and hermetically sealed broth
People argued that the vegetative force required for life was destroyed and could not be let in.
What was Louis Pasteur’s second experiment?
He created swan neck flasks that could let air in, but no airborne microbes
What was the independent variable in Pasteur’s second experiment?
Whether the flaks neck was intact or broken off:
Control: Intact
Treated: Broke
What was the result of Pasteur’s second experiment? Which theory did this support?
Intact had no microbes
Broke had microbes within a day
Biogenesis
What is biogenesis?
The belief that living things come only from other living things by means of reproduction (living things needs parents)
If biogenesis is true, how did the first organisms arise?
Abiogenesis (covered in the first card set)
Who is Robert Koch?
Discovered anthrax bacillus (put infected blood in clean blood -> caused disease)
Discovered bacteria spores and suggested burning or burying dead animals in cold soil.
1876 - Launched the field of medical biology
Known also for tuberculosis, cholera, and other diseases
What are the four postulates Koch established to determine the cause of most infectious diseases?
- The organism must always be present in a diseased individual.
- The organism must be isolated from the diseased host and grown in a pure culture.
- Samples of the pure culture must cause the disease when inoculated into a healthy laboratory animal (e.g., guinea pig).
- The organism must be isolated from the inoculated animal and identified as the same organism first isolated from the original diseased host.
