BIOL354 Lecture Notes - Lecture 7: Lipophilicity, Lipophobicity, Solvent

• School: University of Waterloo
• Department: Biology
• Course: BIOL354
• Professor: Vivian Dayeh

Document Summary

Question: why do some chemicals bioconcentrate: because of lipid solubility lipophilicity. If a chemical is hydrophilic lipophobic -repelled by lipids. If a chemical is hydrophobic lipophilic -prefers lipids or fats: bcf is related to the lipid solubility, higher bcf is associated with increased solubility in lipids, positive linear relationship. Lipophilicity (hydrophobicity) can be measured with the octanol-water partition coefficient (kow: kow measures the behaviour of a chemical between water & an organic solvent. Octanol is used as a surrogate to represent all biological lipids: determining kow. Take equal volumes of distilled water & octanol. Add known amount of chemical & mix well. Low kow chemical is mostly found in water. Biomagnification: an increase in the concentration of a chemical as one moves up the food chain, bioaccumulation deals with same species r group not food chain. Chemical has to bioconcentrate & be persistent in the body (i. e. not eliminated quickly) body burden.