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Micro
Ch.7
56
Microbiology
Undergraduate 3
05/04/2013

Additional Microbiology Flashcards

 


 

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Term
Microbial nutrition
Definition
A process by which chemical substances (nutrients) are acquired from the environment and used in cellular activities
Term
All living things require
Definition
C,H,O,P,N, and S
Term
Essential nutrient
Definition
Any substance that must be provided to an organism
Term
Macronutrients
Definition
Required in relatively large quantities and play principal roles in cell structure & metabolism. (C,H,O)
Term
Micronutrients
Definition
Aka trace elements, present in smaller amouts and are involved in enzyme function and maintenance of protein structure. (Mn,Zn,Ni)
Term
Carbon sources
Definition
Required for producing nearly all cell components.
Term
Heterotroph
Definition
Must obtain Carbon from organic sources
Term
Autotroph
Definition
Use inorganic CO2 as their carbon source
Term
Nitrogen sources
Definition
Necessary for the production of DNA, RNA, ATP, & amino acids. Some bacteria and algae utilize inorganic nitrogenous nutrients. Small number can transform N2 into usable compounds through nitrogen fixation. Must be converted to NH3 (ammonia).
Term
Oxygen sources
Definition
Necessary for biomolecule production and ATP synthesis. Can be obtained from both organic and inorganic sources.
Term
Hydrogen sources
Definition
Necessary for maintaining pH, forming hydrogen bonds, serving as the source of energy in oxidation-reduction reactions, and production of biomolecules.
Term
Phosphorus Sources
Definition
Necessary for the production of DNA,RNA, ATP, and phospholipids.
Term
Sulfur sources
Definition
For the production of select amino acids and is vital for tertiary protein structure. Obtained by consuming sulfur-containing organic molecules.
Term
Growth factor
Definition
An organic compound that cannot be synthesized by an organism and must be provided as a nutrient. (EX: amino acids, fatty acids, & vitamins)
Term
Phototroph
Definition
Microbes that photosynthesize & use light for energy.
Term
Chemotroph
Definition
Microbes that gain energy from chemical compounds.
Term
Photoautotroph
Definition
Photosynthetic, considered the primary produces on the planet. (EX: cyanobacteria)
Term
Chemoautotroph
Definition
Chemical energy from inorganic sources.
Term
Chemoorganic autotroph
Definition
Use organic compounds for energy & inorganic compounds as a carbon source.
Term
Lithoautotroph
Definition
Rely totally on inorganic minerals.
Term
Methanogens
Definition
Produce methane from hydrogen gas and carbon dioxide.
Term
Saprobes
Definition
Free-living microorganisms. Feed primarily on organic detritus from DEAD organisms. Primary decomposers on the planet. Rigid cell wall, release enzymes to digest food.
Term
Obligate saprobes
Definition
Exist strictly on dead organic matter in soil & water.
Term
Facultative parasite
Definition
When a sap robe infects a host, usually when the host in compromised.
Term
Parasite
Definition
Chemoheterotroph that derives nutrients from the cells or tissues of a LIVING host. Also called pathogens bc they cause damage to tissues. 3 classifications
Term
Ectoparasites
Definition
Live on the body. (ring worm)
Term
Endoparasites
Definition
Live in organs & tissues.
Term
Intracellular parasites
Definition
Live within cells. (virus)
Term
Obligate parasites
Definition
Unable to grow outside of a living host!
Term
Temperature Adaptations
Definition
3 critical temps. Minimum, maximum, & optimal.
Term
Psychrophilic
Definition
Optimal temp is -5-15˚C. Cannot grow about 20 degrees celsius. Found in frigid ocean waters.
Term
Psychrotrophic
Definition
Optimal temp is 20-30˚C. Common cause of food spoilages. Found in cool soil and water.
Term
Mesophilic
Definition
Accounts for vast majority of medically important microbes. Optimal temp is 20-40˚C. Found in soil, water, plants & animals. Some can withstand short periods of higher temp (thermoduric).
Term
Thermophilic
Definition
Optimal temp is about 45˚C. Some can survive up to 100˚C, where most enzymes are destroyed. Found in hot springs, compost heaps and water heaters.
Term
Hyperthermophilic
Definition
Optimal temp is 80-120˚C. Usually archaea. Found in hydrothermal vents in the ocean floor.
Term
Aerobe
Definition
Can use gaseous oxygen in its metabolism & possesses the enzymes needed to process toxic oxygen products.
Term
Obligate aerobe
Definition
Cannot grow without oxygen.
Term
Facultative anaerobe
Definition
An aerobe that does not require oxygen and is capable of growth in the absence of it.
Term
Microaerophile
Definition
Does not grow at normal atmospheric concentrations of oxygen but requires a small amount of it in metabolism.
Term
Anaerobe
Definition
Lacks the metabolic enzyme systems for using oxygen in respiration.
Term
Obligate anaerobe
Definition
Also lacks the enzymes for processing toxic oxygen and cannot tolerate any free oxygen in the immediate environment & will die if exposed to it.
Term
Aerotolerant anaerobe
Definition
Does not utilize oxygen but can survive and grow to a limited extent in its presence.
Term
Canophile
Definition
Grow best at higher CO2 levels than are normally present in the atmosphere.
Term
Neutrophilic
Definition
Prefer pH of 5-8. Don't grow well in extremes bc it inhibits enzyme function.
Term
Acidophilic
Definition
Grows best at pH below 5.5. EX: helicobacter & lactobacillus
Term
Alkalophilic
Definition
Grow best at pH above 8.5. Found in alkaline lakes and soil.
Term
Facultative halophile
Definition
Don't normally reside in high-salt environments but some can survive up to 20% NaCl. (EX: staphylococcus)
Term
Obligate halophile
Definition
Requires at least 9% of NaCl but is optimal is ~25%
Term
Binary Fission
Definition
Parent cell enlarges & duplicates all it's genetic material.
DNA copies move to opposite ends of the cell membrane.
New cell wall forms between daughter cells.
Cells separate or may remain attached forming chains/clusters.
Term
Generation time
Definition
The time required for a complete fission cycle. Average is 30-60 minutes. Range is from 10-20 min to 10-30 days. Most food-borne pathogens take 20-30 min.
Term
Bacteria growth
Definition
Is exponential. 2->4->8->16->32
5 phases
Term
Lag Phase
Definition
Period of slow or no growth. Cell are producing the molecules necessary for growth.
Term
Log (exponential) phase
Definition
Period of optimal growth & reproduction. Will continue as long as there are nutrients and space.
Term
Stationary phase
Definition
Cell death balances out cell reproduction. Decreased nutrients, accumulated wastes, increased cell density.
Term
Death phase
Definition
Cell death outpaces cell reproduction. Caused by depletion of nutrients. 99% of viable cells die.
Term
Phase of prolonged decline
Definition
The "fittest" cells can survive on the nutrients released by dying cells. Can last for months to years.
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