http://www.youtube.com/watch?v=ERLtyaugzw4 (DDT – start at 2:30)
BIOACCUMULATIONBioaccumulation is the gradual build up of a chemical in aliving organism over time
BIOACCUMULATIONUptake describes the entrance of a chemical into anorganism.Uptake can occur during activities such as eating, drinking,breathing, and touching/contact.SNIFFSNIFF
BIOACCUMULATIONUptake occurs when a chemical passes from the environmentinto an organism’s cellsSemipermeableChemicals tend to move, or diffuse, from areas of highconcentration to areas of low concentrationUptake often depends on the relative concentration of thechemical in the environment compared to the organism’scells
BIOACCUMULATIONStorage means the deposit of a chemical in body tissue or inan organ.
BIOACCUMULATIONStorageCompounds that are highly water soluble do NOT usuallybioaccumulate in an organism’s cells.EXAMPLE:Vitamin D (fat-soluble) Vitamin C (water-soluble)Easy to overdose Hard to overdose
BIOACCUMULATIONStorageBut cobalt is highly water-soluble. Why is it easy toaccumulate this heavy metal?Because cobalt binds tightly and specifically to sites in theliver and accumulates
BIOACCUMULATIONBIOMAGNIFICATION is a process that results in theaccumulation of a chemical in an organism at higher levelsthan are found in its food.
BIOACCUMULATIONBIOMAGNIFICATION can be beneficial or harmful
BIOACCUMULATIONBIOMAGNIFICATION occurs when a chemical becomes moreand more concentrated as it moves up through a food chainTYPICAL FOOD CHAIN:Phytoplankton Zooplankton Small Fish Bigger Fish Mammals
BIOACCUMULATIONThe process of bioaccumulation…-Is a normal and essential process for the growth and nurturing oforganisms-All animals, including humans, bioaccumulate vital nutrients suchas proteins, fats, carbohydrates, vitamins, and minerals
BIOACCUMULATIONBioaccumulation is the net result of the interaction of uptake,storage, and elimination of a chemicalElimination is the removal of chemicals from the organismthrough metabolism (all the chemical reactions in anorganism)1) Chemicals that are easilyeliminated from an organism donot bioaccumulate.2) Chemicals that dissolve readilyin fat have a greater potential toaccumulate
BIOACCUMULATIONOther factors that affect bioaccumulation:-Duration of exposure-Concentration of chemicals in the environment-Lifetime of organism-Anatomy of organism (certain anatomies enable betteraccumulation of specific chemicals)Example:Poison dart frogs accumulatepoisons ingested from eatingants, centipedes, and mites touse as their own poison
BIOACCUMULATIONSUMMARYBioaccumulation is necessary for growth and the acquisitionof essential chemicals……but can be harmful at the same time.