BIOL354 Lecture Notes - Lecture 4: Aryl Hydrocarbon Receptor, Sydney Tar Ponds, Organochloride
9 Jun 2013
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Document Summary
Review: ammonia toxicity is modified abiotically primarily by ph & secondarily by temperature, they are the parameters that change the [un-ionized ammonia] (increase/decrease in [h+ ions]) Pahs (polysistic aromatic hydrocarbons) naturally found in crude oil & coal deposits. If unsuccessful, costly alternative: excavate & treat sediments offsite. Mixture of organic geological substances (e. g. oil, bitumen & coal). Provides energy, fuel, lubrication, power, & are sources of synthetic plastics. Lipophilic, persists in soils (approx 60% of canada"s contaminated sites). Lighter hydrocarbons: more valuable, toxic, volatile & mobile. Due to their lipophilic nature, can be a problem @ distances away from point of release. Heavier hydrocarbons: more absorbed into sediments, more persistent & are less bioavailable compare to lighter mw: bioavailable: absorption across membrane from environment into the organism"s blood stream (intravenously: 100% bioavailable, polycyclic/polynuclear aromatic hydrocarbons (pahs): 2+ fused aromatic (benzene) rings (very stabilized structures) -> persistency.
