Intro to Microbioloy Flashcards
Zacharias Janssen
Created the first compound microscope (uses more than one lens for magnification) Magnification ranged 3x to 9x
Robert Hooke
Presented the first published depiction of a microorganism, the micro-fungus Mucor
Anton van Leeuwenhoek
First person to observe and describe protozoa, red blood cells, the sperm cells of animal and bacteria. He had no scientific training
Aristotle
Spontaneus Generation Theory
Abiogenesis
Theory that addreses the actual origins of life on Earth; Scientists speculate that life may have arisen as a result of random chemical processes happening to replicating molecules.
Francesco Redi
Disproved spontaneous generation for large organisms by showing that maggots arose from meat only when flies laid eggs in the meat
John Needham
Needham’s hypothesis was that of spontaneous generation in a broth.
He boiled broth in a flask and let them cool and then later bacteria appeared.
Lazzaro Spallanzani
He boiled broth in a sealed flask and let it cool but at the end, bacteria did NOT appear.
Spallanzani concluded Microbes come from the air, and boiling will kill them.
Louis Pasteur (Broth experiment)
Disproved the theory of spontaneous generation using swan-neck flasks
Concluded that living things only come from other living things by means of reproduction. Therefore, modern life does not arise from nonliving material.
Louis Pasteur
Father of Microbiology
Proposed the Germ theory of disease
Pasteurization
Anthrax Vaccine
Rabies vaccine (Pasteur treatment)
Germ Theory of disease
States that many diseases are caused by microorganisms.
These small organisms are too small to see without magnification and invade humans, animals, and other living hosts. Their growth and reproduction within their hosts can cause disease.
Louis Pasteur & Charles Chamberland
Experimented with Inoculation of an attenuated chicken cholera bacteria and discovered it does not cause disease, conceptual breakthrough for establishing protection against disease.
How did Chamberland accidentaly discover attenuated strains prevent diseases?
He left a culture growing over a short vacation ( he was supposed to inject the chickens before leaving, but he forgot)
When he returned, he injected the chickens anyway but they didn’t get sick or die.
Admitting his mistake, Pasteur said to inject the chickens with a fresh culture and they still did not get sick.
Joseph Meister
First-person inoculated against rabies by Louis Pasteur. A 9-year-old who was badly bitten by a rabid dog.
Louis Pasteur (Rabies vaccine)
The vaccine consisted of a sample of the virus harvested from infected/rabid rabbits, which was weakened by allowing it to dry for 5-10 days.
Robert Koch
Founder of modern microbiology
Groundbreaking research on tuberculosis
First, to link a specific microorganism (Anthrax) to a specific disease, rejecting spontaneous generation and supporting the germ theory of disease.
Koch’s First Postulate
The microorganism must be found in abundance in all organisms suffering from the disease but should not be found in healthy organisms.
He abandoned the first postulate when he discovered asymptomatic carriers of cholera and typhoid.
Koch’s Second Postulate
The microorganism must be isolated from a diseased orgaism and grown in pure culture.
Second postulate may also be suspended for certain microorganisms or entities that cannot be grown in pure cultures, such as prions.
Koch’s Third Postulate
The cultured microorganism should cause disease when introduced into a healthy organism.
Third specifies should and not must because as Koch himself proved in tuberculosis and cholera, not all organisms exposed to an infectious agent will acquire the infection.
Koch’s Fourth Postulate
The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.
Koch’s Postulates
Definition
Four criteria that were established to identify the causative agent of a particular disease.
Why learning microbiology is essential in the veterinary curriculum?
Because you need to acquire knowledge about the infectious diseases of animals
Diagnose, treat, Prevent
One Health
Interface between Humans, Animals and the Ecosystem.
The collaboratuve effort of multiple
Global Health
Zoonotic Disease Control
Outbreak Preparedness
Address Antimicrobial Resitance
Food Safety and Security
Beneficial microbes
Probiotics and fermentation (yogurt cheese, alcohol, wine, beer)
Antibiotics ( penicillin, streptomycin, chloramphenicol)
Vaccines, Vitamins, Enzymes
Harmful microbes
Diseases
Food spoilage
Essential Component of an Ecosystem
Cycling important nutrients (S,C,N)
Nitrogen Fixers
Methanogenic bacteria (Natural gas production)
Bioremediation ( Microbes restore stability to disturbed or polluted environments)
Transmision Electron Microscope
Tomography
Transmits electrons through an ultrathin section to show internal ultrastructural features, such as a nucleus
Microtome
Tool used for cutting ultra thin sections 80nm
Scanning Electron Microscopy
Produces images of a sample by scanning it with a focused beam of electrons, to reveal information about the samples’s surface topography.
Specimens are usually whole and not cut into section, sputter coated with an inert metal, such as gold before scanning can be done.
Protocell
First cells on earth
self-organized, endogenously ordered, spherical collection of lipids/molecules proposed as stepping-stone to the origin of life.
Proto = the first
Joseph Lister
Father of antiseptic surgey
Sterile surgery using Carbolic Acid (killed entozoans endoparasites)
Introduced clean gowns and insited on hand-washing
Developed method for isolating a pure culture of bacterium, named as Bacterium lactis (Lactococcus lactis)
Edward Jenner
Used cowpox as a vaccine against smallpox
“less pathogenic agent could confer protection against a more pathogenic one”
Lady Mary Wortley Montagu
‘Variolation’ used live smallpox virus in the liquid taken from a smallpox blister in a mild case of the disease.
Variolation
Inoculation
method first used to immunize an individual against smallpox (Variola) with material taken from a patient or a recent variolated individual in the hope that a mild, but protective infection would result.
Rudolf Virchow
The father of modern pathology
Coined the term zoonosis (link between human and animal diseases) Veterinary pathology.
Alexander Fleming
Discovered that lysozyme could kill bacteria, the first body secretion shown to have chemotherapeutic properties
Discovered the first antibiotic Penicillin (Nobel prize)
Ferdinand J. Cohn
Classified bacteria into 4 groups based on shape ( spherical, short rods, threads and spirals)
First to show that Bacillus can change from vegetative state to an endospore state when subjected to an environment deleterious to the vegetative state.
Édouard Chatton
First characterized the distinction between the eukaryotic and prokaryotic systems of celullar organization based on presence or absence of nucleus
Prokaryotes - no true nucleus
Eukaryotes - Have a nucleus
Elie Metchnikoff
Father of Natural immunity
Described Phagocytosis ( the eating of cells)
Phagocytosis
A defensive rpocess in which the body’s white blood cells engulf and destroy microorganisms.
Giovanni Battista Grassi
Known for his work on parasite life cycles
David Bruce
Investigated ‘Malta fever’ (brucellosis) and trypanosome, identifying the cause of sleeping sickness. The kinetoplastid (Excavata) protist/protozoan we now call Trypanosoma brucei
Also described Chagas disease (American trypanosomiasis) caused by Trypanosoma cruzi
Dmitri Ivanowsky
Discovered viruses
Filterability of an infectious agent cause tobacco mosaic disease
Infectous agent smaller than bacterium
All Biological Macromolecules are made of 6 major elements
Carbon -present in all
Hydrogen -present in all
Oxygen - present in all
Nitrogen
Sulphur
Phosphorus
What all living things have in common?
Have a plasma membrane
Use ATP fro energy
Genetic information in DNA
Systems of clasification
Dynamic theories developed by us to express particular views about the history of organisms.
Taxonomy
Science of clasification of living object
Taxo ( orderly arrangement)
Common reference source
Dynamic area of science ( DNA- Molecular Phylogenetics, now genomics etc)
Systematits
Scientists who work on taxonomy
Aristotle (Taxonomy)
Used Structural complexity
Behaviour
Degree of development at birth
500 organisms in 11 categories
Some of which are still maintained (vertebrates and invertebrated)
Carl Linneaeus
Two kingdoms
Vegetablia
Animalia
Binomal nomenclature ( formal naming of a living organism)
What is a species?
For sexually reproducing organisms, a species is a population that can breed and produce fertile offspring.
For asexually reproducing organisms like bacteria, the species distinction is trickier
What is Molecular Biology?
The study of the molecular foundation of the processes of replication, transcription, translation and cell function.
Central Dogma of Molecular Biology
Where genetic material is transcribed into RNA and then translated into protein.
- Undergoing revision in light of emerging novel roles for RNA
- First stated by Francis Crick
Francis Crick
First to state the Central Dogma of Molecular Biology
The genetic material must be able to:
- contain the information necessary to construct an entire organism
- pass from parent to offspring and from cell to cell during cell division.
- be accurately copied
- account for the known variation within and between species
Frederick Griffith
British bacteriologist: epidemiology and pathology of bacterial pneumonia (Streptococcus pneumoniae)
BACTERIAL TRANSFORMATION!
- Strains that secrete capsules look smooth and can cause fatal infections in mice
- Strains that do not secrete capsules look rough and infections are non-fatal in mice
Frederick Griffith’s conclusion
Genetic material from the heat-killed type S bacteria had been transferred to the living type R bacteria.
This trait gave them the capsule and was passed on to their offspring
Griffith did not know the biochemical basis of his “ transforming principle”
Colin MacLeod
Oswald Avery
Maclyn McCarthy
Used purification methods to reveal that DNA is the genetic material.
Added RNase, DNase and proteases from which RNase and protease had no effect.
With DNase no transformation concluding that DNA is the genetic material.
Rosalind Franklin
X-ray diffraction of wet DNA fibers. Her crystallography enabled Watson and Crick to unravel the double helix structure of DNA.
Linus Pauling
His method of working out protein structures using simple ball and stick models was later used for Watson and Crick model of the structure of the DNA double helix.
Watson and Crick
Proposed the structure of the DNA double helix.
Erwin Chargaff
Analyzed base composition of DNA that also provided important information.
What is a nucleic acid?
A polymer that consist of a chain of nucleotides.
Building blocks of a nucleotide
- Phosphate
- Sugar
- Nitrogenous base
Characteristics of DNA
- Double stranded
- Helix
- Sugar-phosphate backbone
- Bases on the inside
- Stabilized by hydrogen bonding
- Base pairs with specific pairing
What are the 3 DNA components?
- Phosphate group
- Pentose sugar (Deoxyribose)
- Nitrogenous base
Name the nitrogenous bases and the group they belong to
Purines (double ring)
- Adenine (A), Guanine (G)
Pyrimidines (single ring)
- Cytosine (C), Thymine (T)
What are the 3 components of RNA?
- Phosphate group
- Pentose sugar (Ribose)
- Nitrogenous base (Thymine (T) substituted for Uracil (U)
What is a Phosphodiester bond?
Phosphate group links two sugars.
What is a nitrogenous base?
A type of organic molecule that consist of one or two ring structures.
