Module 1: Introduction to Microbiology Flashcards
(30 cards)
What are the 3 properties of ALL microbial cells?
- Metabolism - the chemical processes that occur in a living organism (GENETIC [DNA,RNA,Protein] or CATALYTIC [biomolecule synthesis])
- Growth (Binary Fission)
- Evolution (Mutation)
What is microbiology?
The study of microorganisms (microbes) which are lifeforms too small to be seen by the unaided eye
What are the properties of SOME microbial cells?
- Differentiation
- Communication [Biofilm - the assemblage of microbial cells in matrix that communicate to increase likelihood of survival]
- Genetic Exchange [vertical and horizontal transmission]
- Motility [flagellum movement]
What are some fields that involve microorganisms and how do they use them?
- Genetics - engineering vaccines, hormones, etc.
- Agriculture
- Food Science
- Immunology - pathogen-host interactions
- Medicine - plans/measures to cure infectious diseases
- Industry - antibiotics, steroids, vitamins, etc.
Robert Hooke’s Contributions
- Earliest rendition of the light microscope
- Published “Micrographia” in 1665
- First known description of microorganisms
Anton van Leeuwenhoek’s contributions
- Built a more precise, smaller version of Hooke’s microscope
- Discovered bacteria (‘wee animalcules’)
Louis Pasteur’s Contributions
- Founded the “pasteurization” method; a method of eliminating bacteria responsible for spoilage
- Swan neck proved that mixture stayed sterilize for longer after heating and slow cooling versus tilted swan neck
- Sterilization is complete killing of all microorganisms in a mixture
Joseph Lister’s Contributions
- Introduced aseptic techniques for surgeries in 1867
Ignaz Semmel’s Contributions
- Introduced handwashing as a method of preventing infections
Robert Koch’s Contributions
- Wrote Koch’s Postulates
- Discovered that association of bacterium with a certain disease did not equal to cause and effect
- Discovered causative agent for tuberculosis and cholera (Mycobacterium tuberculosis and Vibrio cholerae)
What are Koch’s 4 postulates?
- Suspected pathogen must be present in all samples of infected animal but absent in all samples of healthy animal
- Suspected pathogen must be grown in pure culture (isolate pathogen from tissue)
- Cells from pure culture must cause disease in a healthy animal
- Suspected pathogen must be re-isolated and shown to be same as the original sample
Who are Robert’s Associates and their contributions?
- Walther Hesse: use of agar in growing colonies (his wife?)
- Richard Petri: invention of the transparent double-sided petri dish
Martinus Beijerinck’s contributions
- The Enrichment culture technique
- Isolating of specific types of microorganisms based on metabolic properties
- Chemically defined mediums to isolate rhizobia
- Identified the Mosaic disease in virology
Sergei Winogradsky’s contributions
- Successfuly isolated notable bacteria from natural samples (nitrifying and sulfur bacteria)
–> Clastridium pasterianium and Azotobacter (anaerobic and aerobic nitrogen fixing bacteria) - Chemolithotropy: oxidation of inorganic chemicals for the generation of energy such as the Beggiatoa
How did Frederick Griffith prove that DNA is a basis of hereditary?
- Used Streptococcus pneumoniae
- 4 trials w/ 4 outcomes:
a) Rough strain - alive mouse
b) Smooth strain - dead moiuse
c) Heat-killed SS - alive mouse
d) HKSS + RS - dead mouse - Virulent strain passed molecule to transform rough strain proving DNA is hereditary
4 Advantages of using RNA sequencing
- Universally distributed
- Functionally constant
- Highly conserved (slowly changing)
- Adequate length to provide a deep view of evolutionary relationships
Taxonomy Vs Systematics
Taxonomy refers to naming, nomenclature, classification, identification, morphology
Systematics refers to evolutionary relationships between organisms, via a phylogenetic tree
- Taxonomy is under systematics
2 Early methods of classification
- Ernst Haeckel Tree
–> TREE OF LIFE, depicted evolutionary relationships between organisms via a branching tree - Robert H. Whittaker Tree
–> FIVE KINGDOM CLASSIFICATION, similar to Ernst’s but fungi was separated
5 Steps to discover evolutionary relationships of microorganisms
- Isolate DNA of each organisms
- Make copies of each rRNA gene by Polymerase Chain Reaction
- Sequence DNA
- Analyze DNA sequencing (for similarities)
- Construct Phylogenetic Tree
3 Domains
Eukarya
Bacteria
Archaea
LUCA
Last Universal Common Ancestor
Bacteria & Archaea classifications
Domain
Phylum
Class
Order
Family
Genus
Specie
Endospore Formation
When bacteria sense extreme conditions, they reproduce then store all genetic materials in the septum (eventually forming the spore); when conditions stabilize, spore is ejected to form vegetative bacteria again
4 Phyla of Bacteria
(ABFP)
(Always Bring Four Pokemon)
- Actinobacteria
- Firmicutes
- Proteobacteria
- Bacteroidetes
