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microbiology
exam 2
64
Microbiology
Undergraduate 2
10/04/2015

Additional Microbiology Flashcards

 


 

Cards

Term
Metabolism
Definition
The set of controlled chemical reactions within cells
Term
Growth
Definition
Increase in the size od a population
Term
Colony
Definition
Aggregation of cells arising from a single parent cell
Term
Biofilm
Definition
A collection of microbes living on a surface in a complex community
Term
Autotrophs
Definition
Organisms that utilize an inorganic source of Carbon (i.e Carbon Dioxide)
"feed themselves"
Term
Heterotrophs
Definition
Catabolize reduced organic molecules(i.e. proteins, carbs, amino acids, fatty acids that they acquire from other organisms)
Term
Chemotrophs
Definition
Organisms that require energy from redox reactions involving inorganic and organic chemicals.
Term
Phototrophs
Definition
Organisms that use light as their energy source
Term
Organotrophs
Definition
Microorganism that acquires electrons from organic sources
Term
Lithotrophs
Definition
Microorganisms that acquire electrons or hydrogen atoms from inorganic molecules
Term
Obligate aerobes
Definition
Oxygen is essential
Term
Obligate anaerobes
Definition
Oxygen is a deadly poison
Term
Singlet Oxygen
Definition
Toxic O2 (white blood cells use it to oxidize pathogens)
Term
Caroteniods
Definition
A pigment that prevents toxicity by removing the excess energy of singlet oxygen
Term
Superoxide radical
Definition
Toxic O2- ( Superoxide dismutase's are produced to detoxify them- without it the organism will die)Anaerobes do not produce
Term
Peroxide anion
Definition
Toxic O2- (makes hydrogen peroxide an antimicrobial agent)-(catalase or peroxidase detoxify)
Term
Hydroxyl radical
Definition
Toxic 02-( Most reactive)
Term
Facultative anaerobes (ex. E. Coli)
Definition
An aerobic organism that can maintain life via fermentation or anaerobic respiration
Term
Aerotolerant anaerobes (ex. Lactobacilli that transform cucumbers into pickles)
Definition
tolerate oxygen by having enzymes that detoxify oxygen's poisonous form
Term
Microaerophiles (ex. H. Pylori ulcer causing pathogen)
Definition
Require O2 levels 2%-10% (found in the stomach)and are damaged by the 21% found in the atmosphere
Term
Nitrogen fixation
Definition
Reducing nitrogen gas to ammonia ( Very few bacteria are able to do this (ex. cyanobactieria and Rhizibium)
Term
Trace elements
Definition
Required in very small amounts
Term
Nitrogen
Definition
Growth limiting nutrient for many organisms: Without the nutrient they cannot build proteins and nucleotides
Term
Psychrophiles
Definition
Grow best at temps below 15 degrees Celsius, They die at temps above 20 degrees Celsius. Live in snowfields, Ice and cold water. Do not cause disease in humans because of temp. Can cause food spoilage in refrigerators.
Term
Mesophiles
Definition
Grow best in 20-40 degrees Celsius. Human pathogens,
Term
Thermoduric
Definition
Mesophiles that can survive brief periods at higher temps.
Term
Thermophiles
Definition
Grow above 45 degrees Celsius. ( compost piles and hot springs
Term
Hyperthermophiles
Definition
Grow in water above 80 degrees Celsius (some up to 135 degrees Celsius.
Term
Neutrophiles
Definition
6.5-7.5
Term
Acidophiles
Definition
Live in mines and in water that runs through mines down to 0
Term
Alkalinophiles
Definition
Live in soil and water up to 11.5 (cholera lives best 9.0)
Term
osmotic pressure
Definition
The diffusion of water across a membrane and is driven by unequal solute concentrations on two sides of such a membrane
Term
Crenation
Definition
Shriveling of cytoplasm
Term
Obligate Halophiles
Definition
Adapted to growth under high osmotic pressure and live in the Great salt late and smaller salt ponds
Term
Facultative Halophiles
Definition
( Staphylococcus Aureus)
Term
S. Aureus
Definition
causes pimples, sties, boils, life threatening scalded skin and toxic shock.
Term
Hydrostatic pressure
Definition
Water exerts pressure in accordance to depth 1 atm to 10 meters.
Term
Barophiles
Definition
Organisms that live under extreme pressure
Term
Synergistic relationship
Definition
Each receives benefits better together than they would alone
Term
Symbiotic relationship
Definition
They become interdependent on eachother
Term
Biofilm Development
Definition
Free living cells
2)Settle on the surface and attach
3)Develop a gooey extracellular matrix and secrete quorum sensing molecules
4)Quorum sensing triggers cells to change their biochemistry and shape
5)New cells arrive possible including new species, and water channels form in the biofilm.
6)Some microbes escape from the biofilm and resume a free living existence , and perhaps form a new biofilm on another surface
3)The slimy matrix adheres the cells together
4)
Term
Inoculum
Definition
Sample
Term
Medium
Definition
Collection of nutrients
Term
Culture
Definition
Microorganisms that grow from an inoculum
Term
colonies
Definition
Cultures that are visible on solid media
Term
1)Environmental specimens
Definition
Taken from ponds, streams, soil, air
Term
Clinical specimen
Definition
Taken from patients
Term
Normal Microbiota
Definition
Microorganisms associated with certain areas of the body without causing diseases
Term
Pure cultures
Definition
Cultures composed of cells arising from a single progenitor
Term
axenic
Definition
pure culture
Term
CFU
Definition
Colony forming unit
Term
Nutrient broth
Definition
contains beef extract and peptones
Term
Agar
Definition
a complex polysaccharide derived from the cell walls of certain red algae.
Term
Defined media
Definition
Exact chemical composition is known
Term
complex media
Definition
exact chemical composition is unknown. contains a variety of nutrients
Term
Selective Media
Definition
contain substances that either enhance or inhibit growth
Term
Enrichment culture
Definition
use a selective medium, and are designed to increase I very small numbers in order to observe them
Term
Cold enrichment
Definition
enrich cultures that are cold tolerant
Term
preserving cultures
Definition
Normally done by refrigeration
Term
lyophilization
Definition
freeze drying
Term
Generation time
Definition
The time required for a bacterial cell to grown and divide
Term
logarithmic/exponential growth
Definition
any given cell divides to form two cells, and then two divide in four, and then four into eight, and eight into sixteen and so on....
Term
Growth curve
Definition
A graph that plots the number of organisms in a growing population over time
Term
Lag phase
Definition
phase in growth curve in which the organisms are adjusting to their enviornment
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