Taxonomy and Structure Flashcards
Define frank pathogen
-Capable of causing disease in any host
-Always considered a pathogen when isolated
Define opportunistic pathogen
-Capable of causing disease given opportunity
-Often commensal part of normal host flora
Define non pathogens
-Don’t really cause disease, unless weakened immune system
Calculate disease
Disease = number of organisms x virulence of organisms / resistance of host
Why are bacterial classification schemes artificial
-Speed up identification process
-Identify bacteria using limited characteristics
What does bacterial nomenclature involves use of
-Binomial system to assign genus and species
-Specific conventions for naming
What is bacterial naming normally based on
-Morphological, biochemical, serological tests
-Nucleic acid profile –> DNA, RNA
-Single cocci
-Paired cocci
-Chain cocci
-Cluster cocci
-Tetrad cocci
-Coccobacilli
-Club shaped bacilli
-Round end bacilli
-Square end bacilli
-Fusiform bacilli
-Vibrios
-Spirillum
-Borrelia
-Treponema
-Leptospira
-Sarcinae
Characteristics of gram positive bacteria
-purple color
-thick peptidoglycan
Characteristics of gram negative bacteria
-red color
-thin peptidoglycan
-lipid rich outer membrane
What does the penicillin binding protein synthesize
-peptidoglycans
What do antibiotics do to amino acids linked to carbohydrates
-break down linkages
-break peptidoglycan
-lyse cell
What does lysozyme of penicillin cause
-cytoplasmic membrane blebbing
hypotonic environment
-membrane fragments
What are mycolic acids and where are they found
-acid fast bacteria
-found in Corynebacterium, Nocardia, Mycobacterium
What is LPS
-lipopolysaccharides
-predominant lipid in outer leaflet of outer membrane of gram negative cells
-prototypical endotoxin
describe flagella and what does it allow
-filamentous appendages composed of flagellin monomers
-allow for motility
describe glycocalyx and what it inhibits
-capsule of slime layer composed of carbohydrates or glycoproteins
-inhibits phagocytosis and antibiotic uptake
describe pili and what does it allow
-filamentous appendage composed of pilin monomers
-allow adhesion (fimbriae) and DNA transfer (sex pili)
bio degrative pathways
-catabolic
-produce ATP
-metabolic end products – acids, bases, gases
biosynthetic pathwyas
-anabolic
-consume ATP
-biopolymers – proteins, lipids, nucleic acids, polysaccharides
what is fermentation
-anaerobic process
-utilization of glucose to create lactic acid and produce ATP
what is respiration
-substrate to oxidized product
-oxidative phosphorylation
what is photosynthesis
-light absorbed by pigments used to generate ATP
define photoautotroph
-self feeding
-energy source is light
-carbon source is CO2
-photosynthetic bacteria
define photoheterotroph
-energy source is light compounds
-carbon source is organic non sulfur compounds
-purple and green bacteria
define chemoautotroph
-energy source is electrons from inorganic compounds
-carbon source is CO2
-hydrogen, nitrogen, iron, and nitrifying bacteria
define chemoheterotroph
-energy source is electrons from organic compounds
-carbon source is organic compounds
-most bacteria, all fungi, protozoans, animals
thermophiles
-min 40-45C
-max 60-80C
-optimum 55-75C
mesophiles
-min 10-15C
-max 35-47C
-optimum 30-45C
psychrophiles
-min -5-+5C
-max 19-22C
-optimum 15-18C
define aerobic
-requires oxygen
-respiration
define anaerobic
-requires no oxygen
-fermentation
-O2 byproducts toxic
define facultative anaerobe
- grows with or without oxygen
-does better in air, but can do fermentation
define microaerophilic
-requires reduced oxygen
define capnophilic
-only grow in air with additional CO2
what are the two basic types of culture media
-defined, simple
-enriched, complex
what is metabolism
-net result of biochemical activities associated with catabolic and anabolic pathways
