Enzymes are specialized proteins that act on specific molecules — called substrates — in the body, increasing the rate of metabolic reactions and changes. There are different enzymes associated with different tasks, such as digestion and metabolism, as well as contributing to the correct functioning of hormones like insulin and glucagon. Many enzymes help break down food molecules and compounds such as lactose and protein, which aid in the proper absorption and assimilation of these nutrients. These digestive enzymes decrease as the body ages, yet can be increased with digestive enzyme supplements and dietary means.
It is often noted that enzymes in the body are responsible for the metabolism, or the breaking down and building up, of all things occurring on a cellular level. There are two main types of enzymes in the body: metabolic enzymes and digestive enzymes. These protein particles act on a specific site on a cell to bring forth a desired result or change. Some of these enzymes help facilitate energy exchanges between cells, whereas others help break down fat and sugar to be used as energy.
Many of the commonly discussed enzymes in the body involve the digestion of certain macronutrients, including protein, carbohydrates, and fat. When an individual consumes a piece of food in which the main calories come from protein, like fish or meat, then an enzyme known as protease helps break down the protein into simpler molecules. These simpler forms are called amino acids, which can be used as a energy source for the body. If the enzymes in the body are not sufficient enough to digest the protein, improper digestion and assimilation of the nutrients will occur.
Lactase is an example of an enzyme that helps break down the lactose, or sugar, found in milk and most other dairy products. Those who are lactose intolerant are normally missing the lactase enzymes in the body. Amylase is the name of the enzyme that digests most starch carbohydrates, including those found in grains, vegetables, and some fruits. The main enzyme responsible for the digestion of fats is lipase, and this helps break down fats into fatty acids. These fatty acids are also used as an energy source and for various physiological functions, such as regulating inflammation and acting upon DNA.