An amino acid is considered a group of molecules that have greater importance when they are part of proteins.
An essential amino acid or indispensable amino acid is an amino acid that can not be absorbed by the body, so they must be ingested in the daily diet. The nine amino acids that humans do not synthesize: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine and histidine.
The six amino acids (cysteine, arginine, glycine, glutamine, proline, and tyrosine) are considered essential in the human diet, that is, their synthesis can be limited in special pathophysiological conditions, such as prematurity in the baby or individuals at risk of catabolism severe.
Also, there are five amino acids that are essential in humans, which means they can be synthesized in the body as: alanine, aspartic acid, asparagine, glutamic acid and serine.
What should be the minimum daily intake of amino acids?
The estimation of the daily demand of the indispensable amino acids is difficult to know; These figures have been subject to considerable revision in the last 20 years.
The recommended daily intakes for three-year-old children are 10% to 20% higher than the adult levels and for children up to 150% higher in the first year of life. Cysteine (or amino acids that contain sulfur), tyrosine (or aromatic amino acids), and arginine are always required in growing babies and children.
Composition of amino acids in protein sources.
Several attempts have been made to justify the quality of various types of proteins that include biological value, net protein utilization, protein efficiency rate, amino acid count protein corrected for digestibility and the complete protein concept.
These concepts are important in the livestock industry, because the relative lack of one or more of the essential amino acids in animal feed would have a problematic effect on animal growth.
Although proteins from plant sources have low concentrations of protein in mass compared to egg or milk protein, they are nonetheless “complete” because they contain at least amounts of all the amino acids that are essential in people’s nutrition.
Eating various plant foods can provide a protein of high biological value. Certain natural combinations of foods, such as corn and beans, soybeans and rice or red beans and rice, in adequate amounts, contain essential amino acids necessary for humans.
In addition, certain types of algae and marine phytoplankton predate the division between animal and plant life on the planet; they have as much chlorophyll as plants do, and also all the essential amino acids, just like proteins of animal origin.