A substance that speeds up the rate of a reaction without being changed or used up itself
A type of sugar: a mono saccharide with 6 carbon atoms (a hexose sugar).
Each enzyme can usually only be the catalyst for a single reaction. For example, the enzyme maltase is the catalyst for changing maltose into glucose. Notice that the name of the enzyme is usually very similar to the substance it works on: maltase works on maltose. Enzymes have the ending -ase.
The action of maltase on this reaction is usually written as:
Some enzymes help to make new substances in the body and others help to break down unwanted substances in the body. Enzymes not only speed up reactions, they also make sure that the reactions happen in the right place and at the right time.