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Tuesday, November 23, 2004

Exam III Material/Chapter 11- Prokaryotes

Please use DNA technology definitions, as a reference for this section.
I) Biotechnology Defined- Intentionally modifying genomes of an organism, by natural and biological modification. It has three goals.
1) Eliminate the undesirable phenotype
2) Combine beneficial traits of two or more organisms, in order to create a valued new organism
3) Create organisms to synthesize products of human need
II) Tools of the Trade
_A) Mutagens- These will change a gene to a desired effect.
_B) cDNA- (complimentary) made by reverse transcriptinase and will produce a product without inserting the gene desired.
_C) Restrictive Enzymes- helps cut DNA at desired area to extract that gene. Sticky= not bluntly cut. Blunt= can be cut and extracted (T A G C T A G)
_D) Vectors- transmit one gene into another
III Idnetifying and Classifying Prokaryotes:
_A)PHENOTIPIC- has existed for 300 years.
__1) Morphology - microscopy
__2)Metabolic differences
___a) colonial/agar color- M. Lutus has yellow colonies

___b) differential/selective agars
___c) fermentation tubes
___d) aerobic and anaerobic differences
__3) Serology- look for proteins of a particular polysaccharide that could indicate the presence of a particular organism.(immunoassays)
__4) Fatty Acid analysis- all organisms will have different fatty acids at different levels, so this test is a last resort due to cost and time consumption.
__1) Nomenclature- suffix is usually Latin and the name reflects a characteristic of the organism.
IV In Ecophysiology, the environment will dictate the function of an organism. Problems and solutions exist in ecophysiology.
_A) Problems:

__ 1) Temperature changes
__ 2) exposure to UV rays, and
__ 3) nutrient and moisture fluctuations.
_B) Solutions:
__1) Endospore formation such as bacillus and clostridium
__ 2) Gists which are temperature sensitive
__ 3) communal populations sense a harsh environment and will differentiate to the conditions.

Nutrients are a problem for these prokaryotes.
A solution to this would be sheathed bacteria, which are the slime layers.
A second solution is to prosthecate. These bacteria can increase their surface are to obtain nutrients.
HOST- is usually resident flora in humans. In plants, rhizobium and legumes make amino acids
Agrobacteriums in plants act like carcinogens in humans.
Quarum Sensing- when a population will sense its density and simultaneously reduce a gene to express. EX: Bioluminescence

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