Growth Rate
values between min. and max. that support growth and metabolism
Minimum
metabolic activity of cells slows down till it is incompatible with survival
Optimal
metabolic activity is maximized, fastest growth rate
Maximum
metabolic activity declines, and high temperature damages proteins, membranes, DNA, etc.
Solute
substances dissolved in the solvent (ex:water)
Osmosis
effort to balance concentration gradient of solutes where water flows from one side of semi-permeable membrane to other
osmotic pressure
the force that drives the movement of water
higher osmotic pressure
bigger the difference in concentration
Isotonic
equal concentrations of solutes inside and outside the cell
hypertonic
HIGHER concentration of solutes outside the cell
(water will flow from inside the cell to the outside)
Cell will shrivel
plasmolysis
plasma membrane shrinks away from cell wall
Halotolerant
can grow at low to moderate salt concentrations
Halophiles
require a high salt environment to grow
hypotonic
LOWER concentrations of solutes outside the cell than inside the cell (water will flow from outside the cell into the cell)
cell will burst
Psychrophiles
cold loving (0-15 degrees C)
Mesophiles
moderate temperature loving (15-45 degrees C)
Thermophiles
heat loving (40-80 degrees C)
Hyperthermophiles
Extreme heat loving ( >100 degrees C)
Acid
pH less than 7
(excess protons (H+) or deficiency of hydroxyl (OH-) ions)
Neutral
pH= 7 (equal amount protons and hydroxyl ions)
Base
pH greater than 7 (excess of hydroxyl (OH-) ions or deficiency of protons (H+))
Acidophiles
grows best in acidic conditions (1-6)
Neautrophils
grows best in neutral conditions (7)
Alkaliphiles
grows best in basic conditions (8-12)
where does the majority of ATP come from in respiration?
electron transport chain
what requires O2 as the final electron acceptor in the electron transport chain?
cellular respiration
strict aerobes
absolute requirement for oxygen; dependent on aerobic respiration for growth
strict anaerobes
exposure to oxygen can be fatal; depend on anaerobic respiration and/or fermentation for growth
facultative microbes
very adaptable; can grow in presence or absence of oxygen
which is easy to grow in the lab, aerobes or anaerobes?
aerobes
sodium thioglycollate
reducing agent that removes oxygen from the environment (establishes oxygen gradient in the tube)
resazarin
color indicator for presence of oxygen
(anaerobic: colorless; aerobic: pink)
-cidal
permanent destruction of a cell
-static
slows or stops growth but if removed the microbes can continue to grow
Sterilant
absolute term used to describe the destruction fall organisms in or on something
disinfectant
reduction of pathogen load to harmless levels; too harsh for tissues so only use on inanimate objects
antiseptic
like a disinfectant, but used externally on tissues to destroy or inhibit the growth of microbes
Sanitization
the process of removing microbes to reduce contamination to safe levels (often used by public, food industry, and medicine to describe "clean")
phenol coefficient
quantitative assessment of the effectiveness of a compound as a disinfectant
Halogens
denature proteins (iodine and chlorine)
Alcohols
dissolve plasma membrane and can denature proteins (isopropanol and rubbing alcohol)
Phenolics
dissolve plasma membrane and denature proteins (lysol, phisohex hand wash)
oxidizing agent
oxidize biological macromolecules (hydrogen peroxide)
Soap and detergent
dissolve plasma membrane
antibiotic
can be consumed, unlike disinfectants and antiseptics
bactericidal
kills the bacteria, effective on actively growing cells
Bacteriostatic
slows or stops the growth and allows the immune system to clear the infection (can no be given to immune compromised patients)
Broad spectrum
kills lots of different microbes
narrow spectrum
selectively kills specific microbes
thymine dimers
covalent linkage between adjacent thymine residues on same strand of DNA