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Lecture 5 Growth and Nutrition
Microbial Growth and Nutrition
81
Microbiology
Undergraduate 1
03/31/2010

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Term
Inorganic Nutrients
Definition
atom or molecule that contains a combination of atoms other than carbon and hydrogen - metals and their salts (MgSO4,FeNO3,NaPO4) gases (O2,CO2) and H2O
Term
Organic Nutrients
Definition
contain carbon and hydrogen atoms and are usually the
products of living things
-methane (CH4), carbohydrates, lipids, proteins, and nucleic acids
Term
Heterotroph
Definition
an organism that must obtain carbon in an
organic form made by other living organisms such as proteins,
carbohydrates, lipids and nucleic acids
Term
Autotroph
Definition
an organism that uses CO2, an inorganic gas as its carbon source - not dependent on other living things
Term
Photoautotrophs
Definition
Energy Source - Light Carbon Source - CO2
Term
Photoheterotrophs
Definition
Energy Source - Light Carbon Source - Organic
Term
Chemoautotrophs or Lithotrophs
Definition
Energy Source - Inorganic
compounds,ex. H2, NH3, NO2,H2S,CO2
Carbon Source - A few bacteria and many
Term
Macronutrients
Definition
required in large quantities; play principal roles in cell structure & metabolism
 proteins, carbohydrates
Term
Micronutrients or trace elements
Definition
required in small amounts;
involved in enzyme function & maintenance of protein structure
 manganese, zinc, nickel
Term
3 groups of Microbes (based on Temp)
Definition
1 Psychrophiles (-10 to 25 degree C)
2 Mesophiles (20 to 50 degree C)
3 Thermophiles (45 to 80 degree C)
Term
chemosynthesis:
Definition
a means of converting inorganic hydrogen sulfide dissolved from rocks into food
Term
Pyrite (fool's gold)
Definition
iron-sulfur compound
Term
X-treme Microbe - eating radioactivity
What's the process?
Definition
1) H2O is split by radioactivity into H2 + O
2) The detached O atoms combine with H2O to make H2O2(Hydrogen peroxide).
3) The peroxide then reactts with an iron-sulfur compound called pyrite (FeS2) producing sulfate ions (SO4) that the microbes can "eat."
4) Each SO4 is lacking 2 electrons which is supplied inside the organism by the leftover H2. The microbes use that reaction to store energy.
Term
Hypertonic
Definition
High salt environment
Term
Halobacteria
Definition
-lived in Great Salt Lake and the Dead Sea
-absorb salt to make their cells isotonic with the environment
Term
isotonic
Definition
Water concentration is equal inside and outside the cell; thus the rates of diffusion are equal in both direction.
Term
Hypotonic
Definition
Net diffusion of water is into the cell; this swells the protoplast and pushes it tightly against the wall.
Term
Hypertonic
Definition
Water diffuses out of the cell and shrinks the protoplast away from the cell wall; process is known as plasmolysis
Term
Only organism that produce ___ ___ are capable of living in O2
Definition
Superoxide Desmutase (SOD)
Term
Obligate aerobes
Definition
oxygen required
Term
Facultative anaerobes
Definition
can live in presence or absence of O2
Term
Obligate anaerobes
Definition
dies in presence of O2; form superoxide radicals causing death of organism
Term
Microaerophiles
Definition
oxygen required in low concentrations
Term
Aerobic (Growth in Semi-solid medium)
Definition
top growth
Term
Mircoaerophilic (Growth in Semi-solid medium)
Definition
growth just below surface
Term
Facultative Anaerobic (Growth in Semi-solid medium)
Definition
growth throughout
Term
Aerotolerant Anaerobic (Growth in Semi-solid medium)
Definition
some growth in O2
Term
Anaerobic (Growth in Semi-solid medium)
Definition
bottom growth
Term
Symbiotic
Definition
organism live in close nutritional relationships; required by one or both members.
Term
3 divisions of Symbiotic Associations
Definition
1) Mutualism
2) Commensalism
3) Parasitism
Term
Mutualism
Definition
Obligatory, dependent; both members benefit
Term
Commensalism
Definition
The commensal benefits; other member not harmed
Term
Parasitism
Definition
Parasite is dependent and get benefits; host harmed
Term
Nonsymbiotic
Definition
Organisms are free-living; relationships not required for survival
Term
2 divisions of Nonsymbiotic
Definition
1) Synergism
2) Antagonism
Term
Synergism (nonsymbiotic)
Definition
Members cooperate and share nutrients
Term
Antagonism (Nonsymbiotic)
Definition
Some members are inhibited or destroyed by others.
Term
Trophosome
Definition
feeding organ of the tube worm Riftia (the organ is filled with bacteria)
Term
Number of Cells = 2 to the power of n
n - number of generation
ex. 32 cells hass how many generations?
Definition
5 because 2 to the power of 5 is 32
Term
Generation time
Definition
the time required for a cell to divide and its population to double
Term
Growth curve
Definition
1) Lag Phase
2) Log or Exponential Phase
3) Stationary Phase
4) Death or Logarithmic decline phase
Term
Lag Phase
Definition
- cells increase in size
- No cell division
- Increase in metabolic activity
- Synthesis of cell components
Term
Log Phase (Exponential Phase)
Definition
- cells dividing at a
constant,exponential maximal rate determined by the organism and
temperature
ex E.coli – 20 min.
Term
Stationary phase
Definition
- Accumulation of waste products
- Exhaustion of nutrients
- Decreased growth rate
- Some cells are dying and
some growing – viable
count remains the same
Term
Death phase
Definition
number of cells dying exceeds number
of new cells formed
Term
Subclinical
Clinical Symptoms
Death
Definition
Subclinical - small inoculation
Clinical Symptoms - greater innoculum
Death - Large inoculum

it takes about 7 days for antibodies to appear
Term
Methane (CH4)
Definition
A greenhouse gas and is produced by burning fossil fuel
Term
Quorom Sensing signaling molecules
Definition
autoinducers
Term
Cystic fibrosis (CF) patients typically develop persistent ___ ____ lung infections that lead to lung failure.
Definition
Pseudomonas aeruginosa
Term
Microbial Control Method
Definition
1)Physical Agents
2)Chemical Agents
3) Mechanical Removal Method
Term
2 divisions of Physical Agents(Microbial Control)
Definition
1) Heat
2) Radiation
Term
Physical Agent Microbial Control(Heat: 2 ways)
Definition
1) Dry (Incineration, Dry Oven)
2) Moist (Sterilization, Disinfectant)
Sterilization - steam under pressure
Disinfectant - boiling H2O, hot H2O, pasteurization
Term
Physical Agent Microbial Control (Radiation: 2 ways)
Definition
1) Ionizing - x-ray;cathode,gamma - Sterilization

2) Nonionizing - UV (Disinfectant)
Term
Chemical Agents Microbial Control(2 ways)
Definition
1) Gases (Sterilization,Disinfectant)
2) Liquid -
Animate - Antisepsis
Inanimate - Disinfection
Inanimate - Sterilization
Term
Mechanical removal methods(3 ways)
Definition
1) Inanimate - Sterilization
2) Animate - Degermation
3) Air and Liquids - Filtration
Term
Disinfection
Definition
The destruction of vegetative pathogens but not bacterial endospores. Usually used only on inanimate objects.
Term
Sterilization
Definition
The complete removal or destruction of all viable microorganisms. Used on inanimate objects.
ex. Autoclave-steam under pressure or a sterilizing gas s.a. ethylene oxide
Term
Degermation
Definition
Chemical and physical methods that reduce the microbial load on the skin. Ex. Mechanical scrubs
Term
Antisepsis
Definition
Destruction of vegetative pathogens on living tissue ex Chemical anti-microbials
Term
Sanitation
Definition
Lowers microbial counts on eating and drinking utensils to safe public levels. ex High temp washing or dipping into a chemical disinfectant
Term
Bacteristatic
Definition
Inhibits the growth - certain antibiotic
Term
Bacteriocidal
Definition
Kills the microorganisms
Term
Sepsis vs asepsis
Definition
Bacterial contamination vs. free of pathogens
Term
Boiling or flowing steam
Definition
Kills vegetative bacterial and fungal pathogens. Most virus with 10 min
Term
Autoclave - protein denaturation
Definition
Most effective. 15 psi pressure at 121 oC. Kills all vegetative cells and
endospores in 15 minutes
Term
Pasteurization
Definition
Heat treatment for milk 72oC for 15
sec. Kills pathogens and most nonpathogens
Term
Dry HEAT Hot-air (incineration or oxidation)
Definition
Effective – 120oC for >2 hrs
Term
Filtration .22um
Definition
Removes organisms
Term
Cold – Refrigeration
Definition
Bacteriostatic effect decreased
chemical reactions
Term
Lyophilization/dessication
Definition
Most effective in Microbial Control
Term
Nonionizing UV (radiation desctruction of DNA)
Definition
produced by electric currents passing through special lamps (e.g. mercury-vapor)
it is virtually nonpenetrating and is mainly used to disinfect air and
surfaces; waste water
Term
ionizing (radiation destruction of DNA)
Definition
Gamma rays and high energy electron beam (Drugs and medical supplies; food)
Term
Biguanides
Definition
used in surgical hand scrubs
 Binds strongly to skin with low
toxicity
 Vegetative cells and viruses with
an envelope
Term
Halogens
Definition
iodine and chloride
 Bacteria, spores, fungi and
viruses
 Chlorine active in water as it
forms hypochlorous acid
 10% solution in contact with
organisms kills most
Term
Hypochlorous acid
Definition
widely used to disinfect swimming pool and drinking water
as the molecule is very reactive with organic matter so it is quickly converted to the more persistent but much less
toxic chloramines
Term
Highest Resistance microbes
Definition
Bacterial endospores
Term
Moderate resistance
Definition
 Pseudomonas sp.
 Mycobacterium tuberculosis
 Staphylococcus aureus
 Protozoan cysts
Term
Least resistance microbes
Definition
 most vegetative cells
 Fungal spores
 enveloped viruses
 Yeast
 Protozoan trophozoites
Term
Ethylene oxide gas
Definition
Alkylating agent - disinfectant used to sterilize heat-sensitive objects such as rubber and plastics
Term
Phenolic compounds (lysol, carboloic acid)
Definition
Antiseptics at low concentrations;
disinfectant at high concentration
Term
Formaldehyde (8%)
Definition
disinfectant; kills endospores
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