Quinoa contains 11 essential amino acids including methionine, and cystine, lysine, tryptophan and valine. Because quinoa supplies all of the amino acids that people need in their diets, it is considered a complete protein and a suitable protein source for vegetarians.
Per gram of protein, quinoa contains 21 milligrams each of methionine and cystine, 51 milligrams of lysine, 8 milligrams of tryptophan and 45 milligrams of valine. Additionally, quinoa contains 30 milligrams of threonine, 25 milligrams of hystadine, 37 milligrams of isoleucine and 64 milligrams of leucine.
The amino acids in quinoa are essential amino acids, meaning that the human body does not naturally produce them and must obtain them from food. Each amino acid has a different function. For example, leucine is important for muscle growth and maintenance. It may also help regulate blood sugar. Isoleucine works to build muscles and promote the production of hemoglobin in the blood.
Quinoa contains a high concentration of phenylalanine. Phenylalanine converts into another amino acid, tyrosine, in the body. Tyrosine has a number of functions in the body, including regulating thyroid hormones. One cup of cooked quinoa contains 8 grams of protein. It is also a good source of dietary fiber, vitamins and minerals.