Amino Acids That Cannot Be Synthesized by the Body & Must Be Provided by Food

Amino Acids That Cannot Be Synthesized by the Body & Must Be Provided by Food

Overview

The human body requires 22 amino acids of which eight are essential for adults, meaning that they must be added from outside sources. In addition, two amino acids called arginine and histadine are also considered essential for infants and small children because of their underdeveloped digestive systems, according to Sareen Gropper in "Biochemistry of Human Nutrition." As your child grows older, histadine becomes nonessential and he may not need to obtain it from outside sources.

Tryptophan and Valine

These amino acids are particularly plentiful in dairy products, soybeans and soy products, nuts, meat, eggs and fish. Tryptophan is structurally the largest amino acid and is used by the body to synthesize serotonin, a brain chemical that regulates mood, sleep and appetite. In the body, valine is helpful in the treatment of liver and gallbladder disorders. Valine also provides energy to your body and helps in tissue repair.

Isoleucine and Leucine

In the body, leucine and isoleucine are broken down and converted to blood sugar, thereby helping the muscles recover after strenuous activity. Both amino acids are primarily energy-yielding sources for your body and enable bones and muscles to heal faster after injury. In addition, isoleucine helps regulate blood sugar levels in your body.

Phenylalanine and Threonine

Phenylalanine occurs in three forms: L-phenylalanine, D-phenylalanine and DL-phenylalanine. In the body, phenylalanine is converted to another amino acid called tyrosine and brain chemicals called epinephrine and norepinephrine. The different forms of phenylalanine may have effects in elevating mood and altering pain sensation. Threonine, needed to create other amino acids called glycine and serine that are necessary for the formation of collagen, elastin and tooth enamel, is a substance that contributes to skin, tendon and muscle flexibility. In the liver, threonine prevents fat from accumulating and helps in the stabilization of blood sugar.

Lysine and Methionine

In the body, lysine helps in production of carnitine, a nutrient that converts fatty acid into energy and helps in lowering cholesterol levels. Lysine is also helpful in the absorption of calcium and is vital in the production of antibodies, hormones and enzymes. Methionine aids in the production of an antioxidant called glutathione that fights against free radicals, damaging compounds that threaten healthy cells in your body. Methionine is also required for the synthesis of hemoglobin, the oxygen-carrying pigment in red blood cells.

source : livestronge.com