Chapter 1: Introduction Flashcards
microorganism
an organism too small to be seen with the unaided eye
types of microorganisms
bacteria, archae, fungi, protozoa, microscopic algae, viruses, multicellular animal parasites
why are viruses considered to be microorganisms?
they are not alive (they do not carry out respiration) but they do impact living things
pathogenic
disease-causing
six things that microorganisms do for us
decompose organic waster generate oxygen treat diseases produce chemical products produce fermented foods produce manufactured products
TEM
transmission electron microscope: views inside a dead specimen
SEM
scanning electron microscope: view surface of specimen
epidemic
widespread outbreak of infectious disease
endemic
localized outbreak of infectious disease
Carolus Linneaus established
system of scientific binomial nomenclature
scientific name consists of
genus and specific epithet
species
two organisms that can mate and reproduce a viable offspring
why is it difficult to classify bacteria?
horizontal gene transfer allows the sharing of genetic material without being related
why was Escherichia coli given its name?
discovered by Theodor Escherich
lives in the colon
three domains of life in order of appearance
archae bacteria - no nucleua
(eu)bacteria - no nucleus
eukaryo - nucleus
prokaryotes
unorganized nucleus
consists of bacteria and archae
bacteria have cell walls made of
peptidoglycan (carbohydrate, peptide protein)
bacteria divide by means of
binary fission
bacteria get energy from
organic or inorganic chemicals
photosynthesis
archae have cell walls made of
they do not have cell walls
archae live in
extreme environments
three examples of archae
methanogens
halophiles
thermophiles
methanogens
produce methane in anaerobic conditions
halophiles
live in environments with high salt concentrations
thermophiles
live in environments with extremely high temperatures or low (acidic) pHs
eukaryotes
have defined nucleus
eukaryotic microorganisms
fungi
protozoa
algae
multicellular animal parasites
fungi cell wall is made up of
chitin
fungi gets nutrients by
absorbing organic chemicals
unicellular fungi
yeasts
multicellular fungi
molds and mushrooms
mold
masses of mycelia, composed of hyphae (filaments)
protozoa get nutrients by
absorbing or ingesting organic chemicals
how can protozoa be motile?
pseudopod
cilia
flagella
where can protozoa live?
free living or parasitic
algae cell wall is made up of
cellulose
algae live in
freshwater, salt water, or soil
algae get energy
photosynthesis
algae produce
carbohydrates and oxygen
multicellular animal parasites are considered microorganisms because
they have microscopic stage in life cycle
helminths
parasitic flat and round worms that have microscopic early life stage
viruses are considered to be
acellular (not living)
viruses genetic material
DNA OR RNA core
virus core may be surrounded by
protein coat
lipid envelope
viruses can replicate when
living in an active host cell
what if a virus is not inside of an active host cell?
it may remain inert for minutes to years depending on the virus
Carl Woese
classified Archae
Hooke
reported living things are composed of little boxes (cells)
marks beginning of cell theory
van Leeuwenhoek
observed first microbes (animalcules) through magnifying glass
spontaneous generation
hypothesis that life arises from nonliving matter
biogenesis
hypothesis that living cells only arise from preexisting living cells
Redi
decaying meat experiment
showed that maggots come from fly eggs, not the meat
supported biogenesis
Needham
boiled broth in covered flask experiment
microbial growth because he did not heat the broth enough
supported spontaneous generation
Spallanzani
boiled nutrient solution in sealed flask
no microbial growth because he heated the broth enough to kill the microbes
supported biogenesis
Pasteur
boiled nutrient broth in flask, one sealed, one open
microbial growth in open flask
demonstrated microbes are present in air - biogenesis
Golden Age of Microbiology
1857-1914, began with Pasteur’s work