Chapter 5 ( pdf 12) Flashcards
Using oxygen as a terminal electron acceptor has
Highest cellular energy yeild
Generation of oxygen radicals highly reactive substances
with an unpaired electron give you
- superoxide radical ( catalase)
- hydrogen peroxide
Multiply between pH of 5 and 8
Neutrophiles
-maintain optimum near neutral
Thrive at pH below 5.5
Acidophiles
Maintains neutral internal pH pumping out protons (H+)
Acidophiles
Grow at pH above 8.5
Alkalophiles
Maintains neutral internal pH through sodium ion exchange
Alkalophiles
exchange sodium ion for external H+
Alkalophiles
10 major required elements for growth
carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorous, potassium, magnesium, calcium, and iron
- it matters what forms these are in for ability of usefulness to different organisms
- ocean as dilute rapidly soluble environment while soil are dry and mineralized by the environment
organisms that are classified based on carbon usage
Heterotrophs and Autotrophs
use organism carbon as energy source
Heterotrophs
use inorganic carbon ( CO2) as carbon source
Autotrophs
5 trace elements
cobalt, zinc, copper,molybdenum, and manganese
- it matters what forms these are in for ability of usefulness to different organisms
- ocean as dilute rapidly soluble environment while soil are dry and mineralized by the environment
Organisms that derive energy from sunlight and chemical compounds
Phototrophs and Chemotrophs
- organisms often grouped according to energy source
derive energy from sunlight
Phototrophs
derive energy from chemical compounds
Chemotrophs
Organism thrive due to their ability to use diverse sources of carbon and energy
Photoautotrophs, Chemolithoautotrophs, Photoheterotrophs,Chemoorganoheterotrophs
use sunlight for energy and atmospheric carbon (CO2) as carbon source
Photoautotrophs
use inorganic carbon for energy and use CO2 as carbon source
Chemolithoautotrophs
energy from sunlight, carbon from organic compounds
Photoautotrophs
use organic compounds for energy and carbon source
Chemoorganoheterotrophs
most common among humans and other animals
Chemoorganoheterotrophs
environmental considerations
Halophiles to extreme
Removal of all microorganisms
– is absolutely free of microbes,
endospores and viruses
Sterilization
Eliminate most pathogens
-some viable microbes may exist
Disinfection
use on inanimate object and surfaces
Disinfectant
used on living tissues
Antiseptics
Most critical consideration
-resistant microbe classes include…
Endospores, Protozoan cysts and oocysts, Mycobacterium species, and Pseudomonas species
resistant to heat, drying, and numerous chemicals
Endospores
generally excreted in feces and cause diarrheal disease
Protozoan cysts and oocysts
cell wall structure initiates resistance
Mycobacterium species
can grow in the presence of many chemical disinfectants
Pseudomonas species
used to sterilize among pressurized steam
autoclave
preferred method of sterilization
autoclave
order of autoclave
heated water-> steam-> increased pressure
what degrees, psi, and time do autoclave achieve sterilization
121 degrees Celsius, 15psi in 15 minutes
what degrees, psi, and time do autoclaves flash?
135 degrees Celsius, 15psi in 3 minutes
autoclaves are effective against…
endospores
useful gaseous sterilant
Ethylene Oxide
Ethylene Oxide destroys microbes including
endospores and viruses
Its mode of action is to react with proteins and DNA
Ethylene Oxide
useful in sterilizing heat or moisture sensitive items
Ethylene Oxide
Limitations of Ethylene Oxide
Mutagenic and potentially carcinogenic
gram negative rod that is one of the most abundant members of our intestinal microflora
Escherichia coli
Sequenced genome, routine research lab strain because of easy growth and manipulations
Escherichia coli
Adaptive metabolism can produce almost everything it needs from a few simple trace elements (Ca, Mg, Fe PO3) and a carbon source (glucose) and nitrogen source (ammonium sulfate)
Escherichia coli
Contrast to Neisseria gonorrhoeae cannot make amino acids and is fastidious
Escherichia coli
