Digestive enzymes

Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside the cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes are diverse and are classified based on their target substrates: proteases and peptidases split proteins into small peptides and amino acids; lipases split fat into three fatty acids and a glycerol molecule; carbohydrases break down carbohydrates such as starch into simple sugars.

Function

Digestive enzymes, primarily produced* in the pancreas and small intestine, break down our food into nutrients so that our bodies can absorb them. If we don't have enough digestive enzymes, we can't break down our food—which means even though we’re eating well, we aren’t absorbing all that good nutrition.

Types of Digestive Enzymes

There are three main types of digestive enzymes:

• Proteases: Break down protein into small peptides and amino acids.
• Lipases: Break down fat into three fatty acids and a glycerol molecule.
• Amylases: Break down carbohydrates such as starch into simple sugars.

Role in Human Digestion

In humans, the process of digestion begins in the mouth, where salivary amylase, a type of amylase, starts to break down starches into simple sugars. This process continues in the stomach, where pepsin, a type of protease, begins to break down proteins. The process is completed in the small intestine with the help of a variety of enzymes, including pancreatic amylase, maltase, sucrase, and lactase, which break down the remaining carbohydrates, and trypsin, chymotrypsin, and carboxypeptidase, which continue the breakdown of proteins.

See Also

• Enzyme
• Metabolism
• Human digestive system
• Pancreas
• Small intestine