Decay

Decay is the breakdown of dead matter by bacteria.

Water increases the rate of decay, this is because bacteria needs moisture to survive, and with a high water concentration the bacteria will be ableto survive as well as multiply.

Higher temperatures increase the rate of decay as the higher the temperature the faster enzymes will respire, althhough if its too hot they will denature. The more respiration done the faster they'll multiply.

Oxygen concentration will also increase respiration causing bacteria to multiply fast, if its of a high concentration.

There are many different ways of perseving food by presenting decay:

-Canning means there is no oxygen and therefore the bacteria can not multiply

-Cooking denatures enzymes

-drying removes water from the bacteria which kills the bacteria, this is done via osmosis

-Freezing slows enzymes down

-Adding salt or sugar removes moisture out of the bacteria via osmosis

-Adding vinegar denatures enzymes as its an acid

Worms and woodlice speed up decay by bacteria as they break the dead matter into smaller pieces, this creates a larger surface area.

Food preservation means there is less waste and food can be transported