You get amino acids from proteins through the process of digestion, where proteins are broken down into their constituent amino acids.
Here's a more detailed explanation:
- Ingestion: The process begins when you consume protein-rich foods such as meat, dairy, beans, or nuts.
- Digestion in the Stomach: In the stomach, gastric juices containing hydrochloric acid (HCl) and the enzyme pepsin begin to break down the complex protein structures. HCl denatures the proteins, unfolding them and making them more accessible to pepsin. Pepsin cleaves the proteins into smaller polypeptide chains.
- Digestion in the Small Intestine: The partially digested proteins (polypeptides) then move into the small intestine. Here, enzymes from the pancreas, such as trypsin and chymotrypsin, further break down these polypeptides into even smaller peptides.
- Hydrolysis by Peptidases: Enzymes called peptidases, located on the surface of the intestinal cells, complete the digestion process. These peptidases hydrolyze the peptide bonds, releasing individual amino acids.
- Absorption: The individual amino acids are then absorbed through the intestinal lining and into the bloodstream. They are transported to various parts of the body to be used for building new proteins, repairing tissues, and performing other essential functions.
In summary, protein digestion is a step-by-step enzymatic process that hydrolyzes peptide bonds, resulting in the release of individual amino acids which can then be absorbed and used by the body. Complete proteins, like those found in beef, poultry, fish, eggs, dairy, soy, quinoa, and buckwheat, contain all nine essential amino acids. Incomplete proteins, like those found in nuts, seeds, beans and some grains, do not contain all nine essential amino acids.
