Digestion begins from the moment you bite into your food. Everything you eat needs to be digested in order to be absorbed and used. Enzymes inside your mouth and stomach start the process by breaking down complex molecules into simpler versions that can be taken into your blood.
Digestive Enzymes in the Mouth
The enzymes inside the mouth are contained inside of the saliva. While the saliva is mostly water -- about 97 to 99.5 percent -- the rest is made up of enzymes, mucus, antibodies and electrolytes. Salivary amylase, lingual lipase and lysozomes are the salivary enzymes located inside the mouth.
Stomach Enzymes
As food moves through the esophagus and enters into the stomach, it is greeted with stomach acid, which helps to activate the enzymes inside the stomach. Lingual lipase, pepsin, gastric lipase and chymosin are the four enzymes at work in the stomach.
Function of Mouth Enzymes
The enzymes inside of your mouth serve two purposes. Two of the enzymes exist to begin the digestion process, while a third exists to help kill dangerous bacteria. Salivary amylase is the enzyme that begins to digest starch inside of food. Lingual lipase is an enzyme that stays neutral in the mouth but is activated when it enters the stomach and works to digest fat. Lysozomes are inside the saliva to kill unwanted bacteria.
Function of Stomach Enzymes
As mentioned earlier, lingual lipase is not secreted by the stomach but accompanies food into the stomach and is activated by stomach acid. The other enzymes are excreted by and work inside the stomach. Pepsin is helpful in breaking down and digesting proteins. Gastric lipase and chymosin are enzymes typically found in the stomach of an infant. Gastric lipase breaks down butterfat in milk and chymosin coagulates the protein in milk.
References
- "Anatomy and Physiology"; Kenneth S. Saladin; 2004
- University of Cincinnati; Digestive System; J. Stein Carter; November 2004
