Amino acids
Amino acids are the basic units that combine to form proteins. When you eat foods that contain protein, the digestive juices in your stomach and intestines break down the protein into amino acids. Then your body uses the amino acids to build the specific proteins your body needs for your muscles, bones, blood, and organs.
Proteins are made up of many different amino acids, but 22 of them are necessary for your health. Your body can synthesize 13 of these amino acids, known as nonessential amino acids, through the regular breakdown of proteins.
You can obtain the other nine amino acids, called the essential amino acids, only by eating the right foods. The essential amino acids are found in the protein of meat, milk, cheese, eggs, vegetables, nuts, and grains. However, only protein from animal sources (meat, dairy, and eggs) contains all nine essential amino acids. Most vegetable protein is incomplete, because it lacks one or more essential amino acids.
It’s important that you eat enough protein from a variety of sources to make sure you take in all the essential amino acids. Adults require about 60 grams of protein a day, and children need about 0.5 gram of protein daily for every pound they weigh. Your body cannot store extra amino acids for alter use, so you must eat foods that contain all the amino acids every day for optimal health.
The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phyenylalanine, threonine, tryptophan, and valine. Nonessential amino acids include aspartic acid, glutamic acid, and glycine, as well as 10 others.
Additional Facts
1. In addition to eating animal proteins, you can get all the essential amino acids by combining certain vegetarian foods, such as peanut butter and whole grain bread, or red beans and rice.
2. Amino acids are molecules that contain both amino (NH2) and carboxyl (COOH) chemical groups.
3. Because they’re made up of long strings of amino acids joined together, proteins are described as necklaces of amino acid beads.
