The simple scientific explanation of an enzyme is a substance produced by living organism that acts as a catalyst to start or bring about a biochemical reaction. Enzymes essentially have the job of speeding up chemical reactions in the body. This helps the cells in the body to complete tasks more quickly and conserve energy. Most enzymes are the catalyst for digestive processes and breathing but others also play a role in blood clotting, wound healing, production and regulation of hormones and immune responses.
Types of Enzymes
There are three main types of enzymes; metabolic, digestive and food enzymes. Each of these groups of enzymes has different functions. Of the three types two are produced by the body, the metabolic and digestive enzymes, the food enzymes are obtained from the food that we eat. Metabolic enzymes are the catalyst for energy and detoxification reactions. They are mainly produced by the liver, gallbladder and pancreas. Digestive enzymes speed up the digestive process and help our bodies to convert food into energy. These are mainly secreted along the digestive tract which includes the stomach and intestines. There are also a number of enzymes in the saliva that assist in the breakdown of foods. Food enzymes also assist in the breakdown of food and some of the enzymes contained in food cannot be produced by the body.
How enzymes work
An enzyme is a protein made up of a chain of amino acids and peptides. Each enzyme is a specific shape and has active sites that bind to a specific substance or molecule. The substance or molecule is known as the enzymes substrate. When the substrate binds with the enzyme by fitting into its active sites and enzyme substrate complex is created. The enzyme causes a slight change in the substrate and weakens a chemical bond. This enables the enzyme to produce the catalyst effect that causes the substrate to be broken down into usable molecules in the body. In general, each enzyme is designed to only act on one substrate. For example the enzyme lactase can only cause a chemical reaction when it is acting on lactose. It is responsible for starting the process that the body needs to undergo to breakdown lactose. The enzyme is not changed by the process and is able to perform this function on many substrates over a period of time.
The following video explains how enzymes work: