History Flashcards
Jan Baptista Van Helmont
Underwear + Wheat after 21 days generates mice
Mice generated by these non-living items also reproduced.
Aristole
First one to suggest spontaneous generation.
Francesco Redi
Spontaneous generation: Hypothesis that maggots were generated by flies which were generated by meat.
- Tested this but found out that the flies were pre-exisiting
- Added cover to flask to prove this observation.
- Conclusion: Bigger organisms are not spontaneously generated but smaller living things (mold on meat) is an open question
Who invented microscope to observe microorganisms?
A. Van Leeuwenhoek
Called protists/bacteria animacules
Louis pasteur
- invented a flask that would prevent organisms from falling in due to gravity
- Discovered sourness of milk + wine fermentation… to prevent this, he heated up these drinks aka pasteurization.
Miasma
Bad “Seeds” in the air that cause disease + smell bad
Antisepsis
Discovered by Lister
Used carbolic acid after surgery to prevent microorganisms to infect wounds .
Koch
- Potato slice guy
(Solid medium that prevents bacteria from moving around but not all bacteria grow on this) - Used gelatin but only bacteria under 28 degrees could be observed as the medium would liquify at this temp + easily injested
- Agar was better as it had a melting point of 100 degrees… so microorganisms active during physiological temperatures could be examined.
Koch’s experiment + discoveries
Anthax kills livestock
- Grew bacteria on plate
- Diseased blood infects healthy blood
- microorg must be found only in sick animals… pathogens!
Found germ responsible for anthrax, TB and cholera.
Koch’s postulates
- Microorganism should only be found in diseased individuals
- Isolate it + grow in a pure culture
- Innoculate with healthy individual to see if it makes them sick
- isolate it again from the new host + repeat
Koch’s postulates for viruses
- Virus isolated from host
- Grow virus in cells of host
- Eliminate with filtration
- Should cause disease in healthy individual
- immune system should be induced by that individual
Fredicks + Relman
- Explores Koch’s postulates at a molecular level
- Nucleic acid sequence of pathogen must be present in all affected tissues only.
- If sequence is detected = disease
- # of copies = severity
Antimicrobial effects of Domagk + Flemming
Domagk: prontosil stain is effective against bacteria due to the sulfanilamide
Flemming: discovered penicilin fungi inhibits growth
Chamberland filter
- Pores are smaller than bacteria
Ivanowsky + toxins
- discovered that toxins (smaller than bacteria) could infect after extract of plant is passed through chamberland filter.
Beijerinck + toxins
- toxin can only replicate in cells; living contagion
Jenner + immunology
- If someone had cattle pox, they are somewhat protected from small pox..
- Called this vaccination.
