B: Chemistry and the Environment

compounds that are present in living organisms but should not normally be found there • eneter the water supply in various ways eg urine washing, disposal of unwanted medicines –> carried to sewage plants –> released to environment due to improper treatment • pharmaceuticals found in drinking water • release of antibodies can result in increased resistance of bacteria

• can be broken down by microorganisms Pros • renewable • can be broken down by microorganisms Cons • weaker than normal plastics –> decompose quicker • corn used for plastic rather than for food

• the creation of syntehtic host molecules that mimic some of the actions performed by enzymes in cells • substrate does not form covalent bonds in the active site of the enzyme –> held in place by other forces eg H bonds, LDFs, ionic • removes toxis materials such as heavy metals • calixarenes are used to remove highly radioactive caesium ions / uranium ions from water

• Helps breakdown oil spills, treat industrial waste and in biological detergents • immobilized enzymes (attached to a filter) can be used in treating waste water • biological detergents help breakdown fats and proteins • saves energy by cleaning at lower temps

The increase in concentration of a substance as it passes up a food chain

• pesticides • absorbed by microscopic plants • larger and larger fish eat it • birds eat the fish • weaken egg shells so they are unable to support the weight of the mother

• Waste incineration, gold mining • absorbed by microorganisms in water • increases in concentration until it reaches tuna • humans eat tuna

An approach to chemical research and chemical industrial processes that seek to minimise the production of hazardous substance and their release to the environment

Mr of desired product / total Mr of all reactants x 100 the higher the % the more efficient the process