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When bacterial populations are heated or treated with antibiotics, at what rate do they die?
constant rate
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What are some factors that influence the effectiveness of antimicrobial treatments?
the number of microbes (the more there are the longer it take to eliminate the population), environmental influences (presence of organic matter often inhibit action of chemical antimicrobials), time of exposure (chemicals antimicrobials require extended exposure to affect more resistant microbials), microbial characteristics
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What has been a long time disinfectant, especially in wine-making?
sulfur dioxide
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What book mentions use of sulfur dioxide for wine-making?
Homer's Odysseus
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What are some common additives as food preservatives?
sodium benzoate, sorbic acid, and calcium propionate
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sorbic acid and sodium benzoate prevent what?
molds from growing in certain acidic foods (cheese and soft drinks)
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what does calcium propionate prevent?
growth of surface molds an the bacillus bacterium that affects bread
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what are added to many meat products (ham, bacon, hot dogs) to preserve it?
sodium nitrate and sodium nitrite
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sodium nitrate and sodium nitrite preserve what things in meats?
pleasing red color (reacting with blood), and prevent germination of any botulism spores
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what are nitrosamines?
carcinogenic products that are the reaction of nitrites and amino acids
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what is the purpose of antibiotics?
ingestoion or injection to treat disease
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what two antibiotics are used in food preservation?
nisin (cheese, to inhibit endospores), natamicyn (pimaricin) (cheese, antifungal)
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many what tend to be more effective against gram-positive bacteria than gram-negative?
biocides
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What genera of gram-negative bacteria are of special interest?
pseudomonas and burkholderia
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why are pseudomonas and burkholderia interesting?
they are unusually resistant to biocides and can grow in some disinfectants and quats
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what is resistance of bacteria related to in their structure?
porins in outer layer
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what group of mycobacteria are extremely resistant to chemical biocides?
mycobacterium tuberculosis
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how must prions be destroyed?
carcasses are incinerated
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normal autoclaving is inadequate in sterilizing what media?
surgical instruments
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what is the WHO and CDC's answer for autoclaving surgical media?
combine sodium hydroxide and autoclave at 134
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the science of heredity
genetics
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the genetic information in a cell
genome
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stuctures containing DNA that physically carry hereditary information
chromosomes
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what does a nucleotide consist of?
nucleobase, deoxyribose, and phosphate group
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set of rules that determine how a nucleotide sequence is converted into amino acid sequence of a protein
genetic code
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genetic makeup, codes for characteristics
genotype
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actual expressed properties in an orgaism
phenotype
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most proteins in structures are either...?
enzymatic or structural
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why will there always be concern about any new safety technology?
is it nearly impossible to prove that something is entirely safe under all conceivable circumstances
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what are "suicide genes"?
genes genetically engineered into organisms so after a time it produces its own toxins and kills itself to ensure safety
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humans may be allergic to what organism? where is it from?
bacillus thuringiensis, fields sprayed with insecticide
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how old is modern technology?
slightly older than 30 years old
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fungi require less what for growth?
nitrogen
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fungi are often capable of metabolizing what that bacteria cannot?
complex carbohydrates (lignin - wood)
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