Lecture 10: Classification of Microorganisms Flashcards
What is Taxonomy?
science of classifying organisms
What is systematics, or phylogeny?
study of evolutionary history of organisms
What did Linnaeus do in 1735?
founded the two kingdoms Plantae and Animalia
What did Murray do in 1968?
founded the kingdom Prokarotae
What did Whittaker do in 1969?
founded 5 kingdom system
Who founded the 3 domain system?
Woese in 1978
How did Eukaryotes originate?
from infoldings or prokaryotic plasma membranes
What are the three domains?
Bacteria, Archaea, Eukarya
Eukaryotic cells: DNA, Histones, First amino acid in protein synthesis, ribosomes, growth
dna: linear
histones: yes
first amino acid: methionine
ribosomes: 80S
growth: mitosis
Prokaryotic cells: DNA, Histones, First amino acid in protein synthesis, ribosomes, growth
dna: one circular; some two circualr; some linear
histones: in archaea
first amino acid: formylmethionine (bacteria) methionine (archaea)
ribosomes: 70s
growth: binary fission
What is Binomial Nomenclature? What does it consist of?
used to consistently and accurately name organisms
- genus
- specific epithet
- always italicized
What is the Taxonomic Hierarchy?
series of subdivisions developed by Linnaeus to classify plants and animals
What is the eukaryotic species?
group of closely related organisms that breed among themselves
What is the prokaryotic species?
population of cells with similar characteristics
What are 3 different ways cells are grown?
culture - bacteria grown in lab media
clone - population of cells derived fro a single parent cell
strain - genetically different cells within a clone
What are the different classifications of eukaryotes? define them.
protista - catchall kingdom for variety of organisms
fungi - chemoheterotrophic; uni/multicellular; cells walls of chitin; develop from spores or hyphal fragments
plantae - multicellular; cellulose cell walls; undergo photosynthesis
animalia - multicellular; no cell walls; chemoheterotrophic
How are viruses classified?
- not part of any domain
What is a viral species?
population of viruses w/ similar characteristics that occupies a particular ecological niche
Classification vs Identification
placing organisms in groups of related species
- matching characteristics of unknown organisms to lists of known organisms
Are gram staining and acid-fast staining useful for bacteria without cell walls?
no
What are biochemical tests?
determine presence of bacterial enzymes
What are rapid identification methods?
perform several biochemical tests simultaneously
What is an automated rapid identification system?
cellular proteins are detected by mass spetrophotometry create a spectrum that can be compared to a database
What is serology?
science that studies serum and immune responses
What is an antiserum?
solution of antibodies is tested against an unknown bacterium
What is a slide agglutination test?
bacteria agglutinate when mixed with antibodies produced in response to bacteria
What is serological testing
can differentiate between species and strains within species
What is enzyme linker immunosorbent assay (ELISA)?
known antibodies and an unknown type of bacterium are added to a well; reaction identifies bacteria
What is western blotting?
identifies antibodies in a patients serum; confirms hiv & lyme disease
What is phage typing?
test for determining which phages a bacterium is susceptible to
Define Flow Cytometry
uses differences in electrical conductivity between species and fluorescence
When is Flow cytometry used?
used to identify bacteria without culturing bacteria
What is DNA base composition?
the moles-percentage of guanine plus cytosine in an organisms DNA
What is DNA fingerprinting?
analysis of DNA by electrophoresis of restriction enzyme fragments of the DNA
What is nucleic acid hybridization?
process of combining single complementary strands of DNA
What is the process of nucleic acid hybridization?
1) heat to separate strands
2) combine single strands of dna
3) cool to allow renaturation of double stranded dna
4) determine degree of hybridization
What are dichotomous keys?
identification keys based on successive questions
Wha are cladograms?
maps that show evolutionary relationships among organisms; base don rRNA sequences