that would be destroyed by other agents. In a different form, it can be used as an antiseptic or a throatwash. It restores the original colour in paintings, by oxidizing the black lead sulfide to white lead sulphate. It can also be used as a source of oxygen in the fuel mixture for many rockets and torpedoes. So on the whole, Hydrogen peroxide is a very useful substance.
Enzymes.
Scientists have proved that if you make a solution of starch and water, and kept it at your normal body temperature, it would take quite a long time before any of the starch molecules transform into glucose molecules. However, inside your alimentary canal, this reaction happens much quicker.
Many chemical reactions can be speeded up by components called Catalysts. A Catalyst alters the rate of reaction, without being converted itself.
Catalysts control almost all the chemical reactions that occur inside the human body. The Catalysts which are found in living organisms are known as Enzymes. .
Enzymes are protein molecules that control most of the chemical reactions inside the human body. How they work can be understood easily. The enzyme provides a surface for the reaction to take place on. On the surface of the enzyme molecule, there is a cavity called the active site. Reactant molecules become trapped in this site and so collide more often. This results in more effective collisions, which will increase the rate of reaction. .
Enzymes have many different uses. One enzyme, called Lipases, speeds up the ripening of food, such as cheese. Proteases are found in washing powders. They are good for removing stains of clothes, like blood. .
In several parts of the alimentary canal, digestive juices are secreted. In these digestive juices lie enzymes, which can speed up the breakdown of large molecules to small ones, by the use of surface area. They are called Digestive enzymes. This breakdown is known as hydrolysis because water is also involved (hydro means water', lysis means splitting').
