Proteins are highly complex substances present in all living organisms(1). Proteins are often called body’s building blocks. They are used to build and repair tissues (2). They also help to fight infections. Examples of foods with protein are meat, fish, seafood, and eggs.
Digestion of proteins start in the mouth. The teeth begin the mechanical breakdown of large pieces to small pieces so that it can be swallowed. The food moved to the stomach via the esophagus (3).
Both mechanical and chemical digestion take place in the stomach. The stomach releases gastric juices containing hydrochloric acid and the enzyme pepsin which initiate the chemical digestion of protein (3).
The chyme leaves the stomach and enters the small intestines, where the majority of protein digestion occurs. The pancreas secretes digestive juices into the small intestines to help break down the proteins into its smallest unit called an amino acid (4).
Protein absorption also happens in the small intestines, which contain microvilli. These are small finger-like structures that increase the absorptive surface area of the small intestines (4).
Once amino acids have been absorbed, they are released into the bloodstream, which takes them to cells in other parts of the body to perform their functions (4).