Oral cavity
In the oral cavity, salivary glands secrete ptyalin. It is a
type of α-amylase, which digests starch into small segments of
multiple sugars and into the individual soluble sugars. Secreted by
small and large salivary glands.
Stomach
The enzymes that get secreted in the stomach are called gastric
enzymes. These are the following:
Pepsin is the main gastric enzyme. As it breaks proteins into
smaller peptide fragments, it is a peptidase.
Gelatinase, degrades type I and type V gelatin and type IV and V
collagen, which are proteoglycans in meat.
Gastric amylase degrades starch, but is of minor
significance.
Gastric lipase is a tributyrase by its biochemical activity, as
it acts almost exclusively on tributyrin, a butter fat enzyme.
Small intestine
Pancreatic enzymes
The pancreas is the main digestive gland in our body. It
secretes the enzymes:
Trypsin, is a peptidase, that breaks down peptides in the small
intestine.
Chymotrypsin, also a peptidase
Steapsin, degrades triglycerides into fatty acids and
glycerol.
Carboxypeptidase, splits peptide fragments into individual amino
acids. It is a protease.
Several elastases that degrade the protein elastin and some
other proteins.
Several nucleases that degrade nucleic acids, like DNAase and
RNAase
Pancreatic amylase that, besides starch, glycogen and cellulose,
degrades most other carbohydrates.
Bile from the liver, which emulsifies fat, allowing more
efficient use of lipases in the duodenum; in converting lipids to
their component fatty acid and glycerol molecules
Proper small intestine enzymes
Several peptidases.
The jejunum and ileum secretes a juice called succus entericus
which contains the following:
Six types of enzymes degrade disaccharides into
monosaccharides:
Sucrase, which breaks down sucrose into glucose and fructose
Maltase, which breaks down maltose into glucose.
Isomaltase, which breaks down maltose and isomaltose
Lactase, which breaks down lactose into glucose and
galactose
Intestinal lipase, which breaks down fatty acids
