decay

factors affecting rate of decay:

temp-

warmer temps=faster rate

reason=enzymes work at higher rate

if its too hot/cold enzymes destroyed and decomposition slows

oxygen availability-

microorganisms need to aerobically respire and survive

water avaliabity-

moise environments=faster rate

reason=water needed for biological processes

no of decay organisms-

more microorganisms/detritus feeders=faster decomposition

compost:

decomposed organic matter used for natural fertiliser

recycles nutrients back into soil

compost bins have extra decomposers, use finely shredded waste, warmth generated, mesh sides that let air in

investigating rate of decay:

observation of milk

lipase breaks milk down and pH of milk decreases

phenolphthalein used becomes colourless if pH falls below 8.3

1. measure 5cm3 of lipase solution and add to test tube

2. measure 5cm3 of milk and add to different test tube

3. add 5 drops of phenolphthalein…