BIOL 2303 Lecture Notes - Lecture 20: Pyrimidine Dimer, Filter Paper, Petri Dish
8 Jul 2020
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Document Summary
Microorganisms in high concentrations of salts and sugars. Molds and yeats are more capable than bacteria of growing in undergo plasmolysis materials with low moisture or high osmotic pressure. The effects of radiation depends on its wavelength, intensity, and the duration. Ionizing radiation (gamma rays, x rays, and high energy electron beams) has a high degree of penetration , effects primarily by ionizing water and forming highly r eactive hydroxyl radicals. Ultraviolet (uv) radiation , a form of nonionizing radiation , has a low degree of penetration and causes cell =damage by making thymine dimers in dna that interfere with dna replication. Microwaves can kill microbes indirectly as materials get hot. Chemical agents are used on living tissue (as antiseptics) and on objects (as disinfectants) Few chemical agents achieve sterility (in comparison to heat treatment, autoclave, etc) Careful attention should be paid to the properties and.
