Microbiology- Exam 1 Flashcards
what is science
study of the natural world
what are the steps of the scientific method?
observation, hypothesis, test/experimentation, theory
a tentative statement that makes predictions
hypothesis
When does a hypothesis become a theory?
when consistency is obtained between hypothesis and experiments/ observations
framework within which observations are explained and predictions are made
theory
a descriptive statement or equation that reliably predicts events under certain conditions
law
simplest explanation is usually correct
Ockham’s Razor
what is microbiology?
study of organisms too small to be seen with the naked eye
bacteriology, mycology, algology, protozoology, virology
branches of microbiology
aspects of microbiology mentioned in the bible
wine (yeast fermentation) and leprosy (a contagious bacterial disease)
when did the science of microbiology begin?
1665
who was the first scientist to observe cells?
robert hooke
First observation of live microorganisms
Van Leeuwenhoek in 1673
fermentation 1857
Pasteur
had all of his troops inoculated with small pox
george washington
Developed a vaccine for smallpox in 1796 by rubbing cow pox under skin
edward jenner
Father of microbiology
louis pasteur
life can arise spontaneously from nonliving matter
hypothesis of spontaneous generation
How did Pasteur disprove the spontaneous generation hypothesis?
demonstrated that microbes are present in nonliving matter- air, liquids, and solids
pour meat broth into flask
pour meat broth into flask, bend neck
pour meat broth into flask, boil
controls for Pasteur’s experiment
how was pasteur lucky?
apparently no endospores in the meat broth
- The same pathogen must be present in every case of the disease.
- The pathogen must be isolated from the diseased host and grown in pure culture.
- The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal.
- The pathogen must be isolated from the inoculated animal and must be shown to be the original organism.
Koch’s postulates
- according to koch’s postulates, a specific infectious disease is caused by a specific microbe
- Koch’s postulates help determine the etiology of disease, the first step in treatment and prevention
- microbiologists use these steps to identify causes of emerging diseases
key concepts of Koch’s postulates: understanding diseases
first pasteurization of grape juice occurred in
1869
first pasteurization of grape juice: how
heated grape juice to kill yeast and it was non-alcoholic so they used it for communion
cellular, respiration, metabolism, contains DNA and RNA, contains ribosomes, contains catalyst
what determines life?
organisms have a true nucleus
eukarya
bacteria and archaea are
both prokaryotic, meaning they do not have a nucleus
the most predominant life form on earth
archaea
Kingdoms of the domain Eukarya
fungi, plantae, and animalia, as well as protists.
all organisms evolved from cells that formed over
3 billion years ago
The DNA passed on from ancestors is described as
conserved
smallest living cell
mycoplasma
the best the human eye can see is
100 micrometers
not technically alive
viruses
how much bigger is an average eukaryotic cell than an average prokaryotic cell with respect to volume?
1000x bigger
what is the most obvious difference between eukaryotes and prokaryotes
size
eukaryotic cells are a million times bigger than a
virus
where the activity occurs on the organelles and in the cell
membrane
- peroxisome
- nucleus
-nucleolus
-rough ER
-smooth ER
-microtubule
-microfilament
-mitochondrion
-plasma membrane
-ribosome
-cytoplasm
-golgi complex
eukaryotic cells: common structures (all)
Vacuole, cell wall, chloroplast
eukaryotic cell structures: plants only
centrosome: centriole, pericentriolar material, lysosome, basal body, flagellum
eukaryotic cell structures: animal cell only
super small
- no membrane
- does have DNA material
- in general no membrane bound organelles
structure of a prokaryotic cell
- cytoplasm
-70S Ribosomes
-plasma membrane
-cell wall
-nucleoid containing DNA
-capsule
-plasmid
-fimbriae
parts of the prokaryotic cell
since there are no membranes, _________ happens in the plasma membrane
activity
3 shapes of bacteria
cocci, bacilli, spirilla
three types of spiral bacteria
vibrio, spirillum, spirochete
Chemical substances such as stored nutrients or cell products (usually for storage)
Inclusions
used for conjugation in certain species
pilus
used for attachment
not always present
looks like hair
can be longer than the cell itself
fimbria
- extracellular material usually made of polysaccharides
- used for attachment
- allows dental plaque to stick to teeth and release acid
capsule
extrachromosomal genetic material
always made of double stranded DNA
plasmid
used for motility; could be anywhere by itself or could be in clumps
flagellum
guts of the cell; lots of reactions occur and water based
cytoplasm
no nuclear membrane, usually singular, circular, haploid, and always made of double stranded DNA
nucleoid
site of protein synthesis
ribosomes