science of classifying, naming, identifying organisms
assigning organisms to taxa based on similarities
non-overlapping group of organism
assigns 2 names to every organism using the genus name and the specific epithet name (species name) which together form the scientific name
How is Bergey's manual used?
for classification of bacteria
what did Carl Woese propose?
adding "domain" to levels of taxonomy
why was "domain" created
greater emphasis was put on comparing organism's genetic material
what di Woese compare in order to determine 3 basic types of cells in which "domain" is based on?
nucleotide sequence of rRNA subunits
what are the 3 basic types of cells (and categories of "domain")?
eukarya, bacteria, archaea
what did Linnaeus propose?
a system of standardizing the naming and classification of organisms based on their similarities
what is Linnaeus' system called?
what are the levels of taxonomy?
species, genus, family, order, class, phyla, kingdom
how many kingdoms did Linnaeus propose?
2 - plantae and animalia
what did Whittaker propose?
5 kingdoms - animalia, plantae, fungi, protista, prokaryotae
what are the stages of the virus lytic replication cycle?
attachment, entry, synthesis, assembly, release
what is microscopy?
passage of light or electrons of various wavelengths through lenses to magnify objects and provide resolution and contrast so the objects can be viewed
what is refractive index?
measure of how much the speed of a wave is reduced inside the medium compared to the speed of the wave in some reference medium
what is numerical aperature?
ability of the lens to gather light
what unit is used to describe microbes?
what is the Gram stain?
differential stain that differentiates between Gram-positive (purple) and Gram-negative (pink) bacteria
what is the importance of the Gram stain?
first step in identifying bacteria
what does Gram stain procedures include?
use of primary stain, mordant, decolorizing agent, counterstain
what is acid-fast stain used for?
differentiation of cells with waxy cell walls
what type of cells does acid-fast stain distinguish between?
mycobacterium and nocardia
what does acid-fast stain help in diagnosing?
what are the results of the acid-fast stain?
pink/red acid fast cells; blue non-acid fast cells
what is a capsule stain?
stains background, but leaves cells colorless
what does capsule staining reveal?
what is the acid-fast stain called?
what is the endospore stain used for?
highlighting presence of endospores produced by general Bacillus and Clostridium
what does endospore stain result in?
green endospores; pink/red negative cells
how does Bergey's manual classify prokaryotes?
into 3 phyla of Archaea and 23 phyla of Bacteria
where is an endospore produced?
within the vegetative cells of Gram-positive genera Bacillus and Clostridium
when does an endospore form?
when nutrients are scarce
why are endospores important?
they are durable, have potential pathogenicity, constitute a defensive strategy against hostile or unfavorable conditions
why are endospores dangerous?
they are very resistant and endospore-forming bacteria produce deadly toxins that cause fatal diseases, such as anthrax, tetanus, gangrene
what are methanogens?
the largest group of archaea; produce methane gas from organic waste, which is useful in sewage treatment
what are thermophiles?
an extremophile requiring temps above 45C in order for DNA, membranes and proteins to function
what are hyperthermophiles?
extremophiles requiring temps above 80C for DNA, membranes and proteins to function
what is a halophile?
extremophile requiring high concentration of salt to keep its walls intact
what are the common names of phototrophic bacteria?
blue-green bacteria (cyanobacteria), green sulfur bacteria, green non-sulfur bacteria, purple sulfur bacteria, purple non-sulfur bacteria
what is nitrogen fixation?
the way in which cyanobacteria reduces atmospheric nitrogen gas to ammonia, which is essential for life on earth
protects body parts such as intestinal tract and vagina from invasion by pathogens; used to produce yogurt and pickles
causes strep throat and "flesh eating" bacteria
bacteria that resemble fungi in that they produce spores and form filaments
what does actinomycetes include?
actinomyces, nocardia, streptomyces
found in human mouths
useful in degradation of environmental pollutants
produces important antibiotics and gives soil its musty smell
endospore-forming bacteria; causes gangrene, tetanus, botulism, diarrhea
an alphaproteobacteria that is important in agriculture since it makes atmospheric nitrogen available as ammonia to plants
betaproteobacteria; causes gonorrhea
gram negative cocci; most common cause of STD in the US; also causes neonatal blindness and pneumonia
what does chlamydia do in a host cell?
forms initial bodies, which change into smaller elementary bodies that are released when the host cell dies
what are helicobacter?
epsilonproteobacteria; causes gastric ulcers
what are the arrangements for cocci?
diplococci (attached in pairs); streptococci (long chains of cocci); tetrads (divide in 2 planes and remain attached); sardinae (divide in 3 planes and remain attached); staphylococci (divide in random planes)
what are the arrangements for bacilli?
single baccillus; diplobacilli (attached in pairs); streptobacilli (long chains); palisade (formed by snapping division, daughter cells attached side-by-side); V-shape (formed by snapping division, daughter cells attached in V-shape)
what are the different types of bacteria reproduction?
binary fission, snapping division, budding
what is the most common type of bacteria reproduction?
useful in sewage treatment
flexible, helicle bacteria that live in diverse environments
causes lyme disease
brucellosis, causes abortion in animals
causes swimmer's ear
broadest classification of viruses
nucleic acid - DNA or RNA
proteinacious capsomere coat surrounding the nucleic acid of a virus
complete viral particle (nucleic acid and capsid) outside of a cell
virus that picks up lipid membrane from host cell during release; plays a role in virus recognition
negative sense ssRNA
ribosome can use only mRNA (+RNA) to synthesize protein, so -RNA carries "RNA-Dependent RNA transcriptase" enzyme in its capsid, which it releases into host cell during uncoating. enzyme transcribes +RNA molecules from -RNA. Translation can then occur.
spreading of malignant tumors (cancer) and invading other organs and tissue
uncontrolled cellular reproduction in multicellular animal; benign (harmless); malignant (invasive, cancer)
what causes neoplasia
environmental factors or oncoviruses