Docstoc

'Enzymes'

Document Sample
'Enzymes' Powered By Docstoc
					                                    ‘Enzymes’

ENZYMES are present in every living thing. They are proteins that are able to
activate chemical reactions in living organisms. A silk worm could not break
out of its cocoon with out enzymes. You could not run a race, digest food or
indeed grow up without enzymes. All of your cells, organs, bones, muscles,
and tissues are run by enzymes. Your digestive system, immune system, bodily
functions, as well as your ability to see, think, feel and breath all depend on
enzymes.

The first person who was interested in how food was digested was a French
scientist. In 1750, he tried a unique experiment where he taught his pet hawk
to swallow a tiny cage containing a piece of meat on a string. The string hung
out of the birds mouth and he would carefully pull the string out of the bird
after 15, 30, 60 minuets. The meat had changed colour and texture. He did
not know it but the he had observed the work of enzymes.

Digestion starts in the mouth with the enzyme Amylase that exists in your
saliva. Your saliva helps you moisten the food but the enzymes also help
breakdown the food … the start of digestion. The digestive system breaks
down the food in two ways:*mechanical digestion- the chewing (in the
mouth) and churning (in the stomach)* chemical digestion- with the help of
enzymes, into substances that cells can absorb and use. This occurs in the
mouth, stomach and small intestine.

There are up to 100 000 different enzymes in one cell. However, each enzyme
is responsible for a single reaction in a cell and the process works like a lock
and a key. An enzyme is a key with a particular shape. It will on the particular
molecules that match its size and shape. Enzymes are usually named
according to the reaction they catalyse. Eg. :-
Fats / lipids - broken down by the enzyme              = lipase
Carbohydrates - broken down by the enzyme              = carbohydrase
Sugars - broken down by the enzyme                     = sucrase
Milk products - broken down by the enzyme              = lactase
Proteins - broken down by the enzyme                    = protease

				
DOCUMENT INFO