Chapter 10 - Classification of Microorganisms

taxonomy

science of classifying organisms (present-day)

phylogeny

evolutionary history of group of organisms (historical understanding)

Archaea

prokaryotic; no peptidoglycan in cell wall (pseudomurein); brached c atoms attached to glycerol by ether linkage; 1st amino acid is methionine

bacteria

prokaryotic; peptidoglycan cell wall; straight c chains attached to glycerol by ester linkage; 1st amino acid is formyl methionine

eukarya

eukaryotic; contains carbohydrates in cell wall; straight c chains attached to glycerol by ester linkage; 1st amino acid methionine

taxonomic hierarchy

domain, kingdom, phylum, class, order, family, genus

prokaryotes definition

population of cells with similar characteristics including morphology, biochemical reactions, and DNA sequences

virus classification

population of (them) with similar characteristics occupying a particular ecological niche

animalia

multicellular; no cell wall; chemoheterotrophic

plantae

multicellular; cellulose cell walls; usually photoautotrophic

fungi

unicellular or multicellular; cell walls of chitin; develops from spores or hyphal fragments

protista

catchall kingdom - for any eukaryotes that don’t fit into other organisms

rapid biochemical methods

several biochemical tests performed simultaneously; each test result assigned number

serology - slide agglutination

specific antibodies ID bacteria

• they derive antibodies from animals

serology - ELISA

enzyme-linked immunosorbent assay

• direct —> detects presence of pathogen in sample

• indirect —> detects patient’s antibodies to pathogen in sample (use secondary antibody to detect the first one)

serology - western blot

identifies antibodies in patient’s serum (purpose: to separate and detect proteins)

phage typing

bacteriophages (viruses that infect bacteria) have specific hosts —> therefore used to ID bacteria

• grown lawn, dot samples, observe clear zones

Fatty Acid Profiles

provides profiles that are constant for a particular species (specific types and quantities of fatty acids in sample)

flow cytometry

uses diff. in electrical conductivity between species or fluorescence (allowing for cell counting, sorting, and identification by measuring light scatter and fluorescence)