unit 1 Flashcards
Microbes
Algae
Helminths
Protozoa
Bacteria
Fungi
Viruses
Fungi
Yeasts, Molds, Mushrooms
Viruses
a) Rely on host to survive
b) Non-living
Why are microbes not all harmful ???
a) part of microbiome
b) decomposers of organic matter
c) used for antibiotics/vaccines
Spontaneous generation (abiogenesis)
Life comes from non living matter
Biogenesis
Life comes from living matter
Subdivisions of microbiology
a) bacteriology
b)Virology
c)Mycology
d)Parasitology
e)Helminthology
f)Immunology
g)Chemotherapy
Robert Hooke
a) Developed compound microscope
b) Observed cells (cork)
c) Developed idea that matter is inside living being
Anton Van Leeuwenhook
a) observed bacteria from teeth scrapings
Louis Pasteur
a) disproved spontaneous generation
b) developed aseptic techniques
c) developed rabies vaccine
d) Fermentation
e) Pasteurization (mild heating to kill microbes)
f) Germ theory
Joseph Lister
a) performed surgery using aseptic techniques
b) cleaned instruments with phenol (carbolic acid)
c) proved microbes cause surgical wound infections
Robert Koch
a) Developed etiology of disease
b) found out that Bacillus anthracis causes anthrax
c) Koch’s postulates
d) rival to Pasteur
etiology of disease
the cause of a disease
Koch’s postulates
proved specific diseases are caused by specific microbes/ helped determine the etiology of disease
Edward jenner
a)created first vaccine using her samples to help treat people
b) vaccination against small pox
Elie Metchnikoff
a) Phagocytosis
b) Cellular theory of immunity
Hans Christian Gram
Developed gram stain
Richard Petri
created petri dishes
Dimitri Iwanowski
Discovered viruses through observation/studying tobacco plants (TMV)
Paul Ehrlich
created “magic bullet” which was a treatment for syphillis
Alexander Fleming
created the antibiotic penicillin
Selman Waksman
discovered streptomycin
Rebecca Lancefield
grouped streptococus
Taxonomy
categorization of organisms
Robbert Whittaker
created the 5 kingdom system
5 kingdom system
1) Monera (prokaryote)
2) Protista (eukaryote)
3) Fungi (eukaryote)
4)Plantae (eukaryote)
5)Animalia (eukaryote)
Eukaryote
a) consists of protozoa, fungi, animals, plants
b)has defined nucleus with nuclear membrane
c) DNA = double stranded linear helix
d) Multi-cellular/ uni-cellular
e) Some have cell walls
f) many organelles
g) goes through mitosis/meiosis
Prokaryotes
a) consists of bacteria only
b) No nucleus or nuclear membrane
c) Unicellular
d) DNA= double stranded circular
e) majority have cells walls which are made of peptidoglycan
f) simple with few organelles
g) goes through ONLY MITOSIS (binary fission)
Monera (part of 5 kingdom system)
-bacteria only
- unicellular
- not used anymore because it lies under 2 domains bacteria and archaea
Protista (part of kingdom)
- consists of protozoa and algae
-mainly unicellular
Fungi ( part of kingdom)
- consists of molds, mushrooms, and yeast
- uni-cellular and multi-cellular
- absorbs organic matter from environment
Plantae (part of kingdom)
- consists of mosses, ferns, plants
- multicellular
-uses photosynthesis
Animalia (part of kingdom)
- consists of sponges, worms, insects, animals
- Multicellular
- ingest organic matter
The 3 domains
- developed by Carl R Woese
- states that there are 2 domains for prokaryotes/ 1 domain for eukaryote
Why is there 2 types of prokaryotic cells?
- differences in rRNA and tRNA
Eukarya domain
includes all eukaryotic cells
Bacteria (true bacteria) domain
includes regular bacteria with peptidoglycan cell walls
Archaea domain
- includes bacteria with cell walls that dont have peptidoglycan
- unusal metabolic processes
- live in extreme environments
Endosymbiotic theory
eukaryotic cells evolved from prokaryotic cells living inside one another
What organelle in animal cell resemble bacteria
mitochondria
What organelle in plant cell resemble bacteria
chloroplasts
How are organisms classifed?
Binomial nomenclature; genus and species
types of microscopes
1) compound light
2)Darkfield
3)Fluorescent
4)phase contrast
5) electron (EM)
Dark field microscope
-examines live microbes that are hard to see with compound microscope
-can not be stained
- specimens appear light against a dark field
Fluorescent microscope
- stain with fluorescent dyes
- uses UV light
-detects microbes in tissue/clinical specimens
Phase-Contrast microscope
- examines internal structures of living organisms
- no stains are used
-used direct/diffracted light rays
Electron (EM) microscope
- beams of electrons used to view objects smaller than 0.2 um
- used to see non-living/ stained/ viruses/ internal structures
Observing microbes in living state
using wet mount: motility / hanging drop
Observing microbes in non living state
uses stains which is a colored dye to emphasize certain features
Simple stain
-uses only crystal violet
- observes shape, size and arrangement of cells
Gram stain
uses 4 reagents
Primary stain (gram stain)
crystal violet
Mordant (gram stain)
Iodine
Decolorizer (gram stain)
Ethanol (alcohol)
Counterstain (gram stain)
Safranin (red)
Gram positive bacteria
-appears blue/purple when gram stain is applied
-has thick peptidoglycan cell wall
Gram negative bacteria
-appear pink/red
-has thin peptidoglycan cell wall
Why do Gram + and Gram - bacteria change color when stained
color varies depending on thickness of peptidoglycan cell wall
Acid fast stain
- cell wall has wax and peptidoglycan
- heat slide with carbofuchsin
-decolorize - counterstain = methylene blue
Acid fast positive color
red
Acid fast negative color
Blue
examples of acid fast bacteria
1) mycobacterium sp
2) M. tuberculosis
3) M. Leprae
Differential stains
Gram stain/ acid fast stain
Special stains
1) capsule (glycocalyx) stain
2)endospore stain
3) Flagella stain
Flagella stain
- uses mordant and carbolfuchsin
-builds up diameter of flagellum/ arrangment and # of flagellum
Capsule (glycocalyx) stain
-used to detect capsule in microbes
-negative stain = india pink
Examples of capsule stain bacteria
pasteurella multocida
Endospore stain
-used to detect endospores
-Heat slide= Malachite green / safranin
Examples of endospore stained bacteria
Clostridium/ Bacillus
what is the purpose of endospores
-allows organism to resist adverse enviromental conditions
what is the purpose of capsules
to resist host defenses such as phagocytosis and lysozyme
