Ch 10: Classification of Microorganisms Flashcards
What is taxonomy?
The science of classifying organisms according to how similar they are to other organisms
What is phylogeny?
The study of the evolutionary history of an organism(s)
Taxonomy produces a ______, while phylogeny produces ______.
- Hierarchy
- Phylogenetic tree or cladogram
The three-domain system is based on similarities in _____.
- ribosomal RNA
- Specifically, 16s rRNA, as is highly conserved across all organisms
In 1990, ______ elevated the three cell types to a level above kingdom, proposing the three-domain system.
Carl Woese
What taxonomic domain is lacking the hairpin loop of 16s rRNA?
Archaea
The membrane lipids of Bacteria and Eukarya are joined to the glycerol backbone by a _____ linkage, while Archaea have a ______ linkage.
- Ester
- Ether
_______ is a bacterium that has a nuclear envelope surrounding its nucleoid. It is present-day evidence that plasma membrane involving could produce a nuclear envelope
Gemmata obscuriglobus
______ is a protist harboring a photosynthetic endosymbiont that resembles modern-day cyanobacteria. It is a modern-day example of endosymbiotic prokaryote living in a eukaryotic cell
Cyanophora paradoxa
When a new prokaryote is discovered and named, it is published into what reference book?
Bergey’s Manual of Systematics of Archaea and Bacteria
What is the order for the taxonomic hierarchy? (mnemonic on other side :D)
- Domain → Drunken
- Kingdom → Kangaroos
- Phylum → Punch
- Class → Children
- Order → On
- Family → Family
- Genus → Game
- Species → Shows
What is a strain?
A variant identified by numbers, letters, or name following species designation
Kingdoms in Eukarya
Animalia
Plantae
Fungi
Protista
Animalia
Multicellular; no cell walls; Chemoheterotrophic
Plantae
Multicellular; cellulose cell walls; usually photoautotrophic
Fungi
Chemoheterotrophic; unicellular or multicellular; cell walls of chitin; can develop from spores of hyphal fragments
Protista
A catch-all Kingdom for Eukaryotic organisms that do not fit other kingdoms
Grouped into clades based on rRNA
Define Bacteria’s:
Cell type
Cell wall
Membrane
First Amino Acid
Antibio sensitivity
rRNA loop
Common arm tRNA
Prokaryotic
Peptidoglycan
Composes of straight carbon chains attached to glycerol by ester linkage
Formylmethionine
yes
Present(only one with an rRNA Loop)
Present
Define Archae
Cell type
Cell wall
Membrane
First Amino Acid
Antibio sensitivity
rRNA loop
Common arm tRNA
Prokaryotic
Varies in composition; contains no peptidoglycan
Composes of straight carbon chains attached to glycerol by ether linkage
Methionine(like the Eukaryotic)
NO
NO
Present
Define Eukarya
Cell type
Cell wall
Membrane
First Amino Acid
Antibio sensitivity
rRNA loop
Common arm tRNA
Eukaryotic
varies in composition contains carbohydrates
Composes of stragiht carbon chains attached to glycerol by ester linkage
Methionine (same in Archaea)
NO
NO
Present
Describe the membrane lipids of the 3 domains
Eukarya and Bacteria with eSTer linkage
Arachaea eTHer linkage
A bacterium with invaginated membrane around the nucleoid
Gemmata obscurigolbus
A protist harboring a photosynthetic endosymbiont, similar to a modern day cyanobacteria
Cyanophora paradoxa
Microbes nomenclature
Genus+species
What is a Strain
A variant of a organism, identified by numbers, letters or name following the species designation. For instance E. coli K12 or S. cerevisiae S28C
Classification
Placing organisms in groups of relates species. Lists of characteristics of known organisms
Only 1% of Prokaryotes have been discovered
Identification
Matching characteristics of an ‘unknown’ organism to a list of known organism
Clinical lab identification
Numerical/ Rapid Identification
Only for enterics
1) Tube with 15 different media is inoculated with an unknown enteric bacteria
2) observe the results and what changes colors
3) Note each positive test, and note the numerical value associated with it, which give you an ID
4) Compare ID to a computerized value chart that indicates what organism it is
Dichotomous keys
Used for identifiation, Simple yes or no answers and follow the chart
Cladograms
Show evolutionary relationships
Serology
Combine a known antiserum with an unknown bacterium.
Determines the relatedness of two different organisms
Slide Agglutination test
Type of serology
Unknown bacteria are placed in a drop of saline on several slides
different antibodies are added to each sample
Bacteria will agglutinate when mixed with antibodies produced against them
ELSA(direct assay)
An enzyme will be linked to an antibody, once added to the unknown bacteria they will bind together, once it is bounded add a substrate that will cause it fluoresce
ELSA(direct assay)
An enzyme will be linked to an antibody, once added to the unknown bacteria they will bind together, once it is bounded add a substrate that will cause it fluoresce
Quick and Readable with a computer scanner
ELISA(Indirect assay)
Requires a second antibody that will bind to the primary one, the secondary antibody will have the enzyme linked to it
advantage of the secondary antibody will have a wider range of use and doesn’t require conjugation
The Western Blot
Lyme disease: Borrelia Burgdoferi
use the bacterias proteins
Proteins separated by size using SDS
Proteins are transferred to a nitrocellulose gel using a capillary action
Proteins are exposed to the infected individual’s serum, which should contain antibodies
antibodies must be detectable
Uses HIV as well
Electroblotting
Used electrocurrent to transfer proteins on to the gel
Phage testing
Petri dish with a spread of agar medium
Added a bacteria to be tested(i.e Staphylococcus aureus)
Let it dry and spot the bacteria with different bacteriophages
Affected cells will be lysed and no growth
!PURE CULTURE!
Fatty Acid Profiles
Bacteria synthesize a wide variety of fatty acids
Gas chromatographs can separate fatty acids
FAME profiles used to identify the bacteria type
Fatty Acid Methyl Ester
!Must be a pure culture!
Flow Cytometry
A focused laser scatters light from these cells and can trigger fluorescence
provides information about cell size, shape, density, and surface
cells can be selectively stained with
antibody coupled to a fluorescent dye
• Can be used to identify bacteria in a
sample without culturing (i.e. Listeriain
milk)
