Reduction of microbial populations to meet a health standard.
4 of 20
Which control is heat?
sterilisation
5 of 20
What are the three types of microorganism control?
Physical Chemical & Antibiotic
6 of 20
What wavelength of UV is used for normal radiation?
200-300nm
7 of 20
Which DNA base becomes a dimer when impacted by radiation?
Thymine
8 of 20
Is normal radiation penetrating or non-penetrating?
Not penetrating - radiation does not go through plastic/paper
9 of 20
Is gamma radiation penetrating or non-penetrating?
Penetrating - radiation will go through any plastic/paper (packaged goods, food, medical supplies)
10 of 20
What is the usual size of a pore in filtration of microorganisms?
0.2µm
11 of 20
What are the chemical controls of microorganisms?
Sterilant, disinfectants, antiseptics
12 of 20
What are the physical controls of microorganisms?
Heat, radiation & filtration
13 of 20
Which radiation is this describing?
Acts on DNA
DNA base covalently joined (dimer) impending replication
Needs to be enough radiation to swamp repair enzymes, so cells will die
UV radiation
14 of 20
What type of radiation is this describing?
Generates free radicals (e-, OH and H) therefore highly reactive
Reacts will cellular constituents
Death from effects on DNA breakdown
Gamma radiation
15 of 20
What is an example(s) of a sterilant?
Ethylene Oxide
16 of 20
What is an example(s) of a disinfectant?
Alcohols, Halogens, Phenols
17 of 20
What factor of survival is this describing?
Changes the osmotic environment
Works by dehydration of the environment
Rupture of cells due to osmotic shock
Interfere with cellular enzymes
Limit oxygen solubility
Expend energy removing sodium ions
Salt
18 of 20
What factor of survival is this describing?
The proton motive force responsible in cellular respiration depends on the concentration gradient of H+ across the plasma membrane
Proteins are the most affected molecule
Many enzymes from alkaliphiles have a h
pH
19 of 20
What is a substance used to protect biological tissue from freezing damage (i.e. that due to ice formation)
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