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Many amino acids are used to
synthesize other molecules, such as tryptophan
which is a precursor of the neurotransmitter serotonin,
and glycine which is one of the reactants in the
synthesis of porphyrins such as heme. Numerous
non-standard amino acids are also biologically
significant: GABA (another neurotransmitter),
carnitine (used in lipid transport within a cell) etc.
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Essential Amino Acids
Some of the 20 standard amino acids are called essential
amino acids. These essential amino acids are indispensable for human life,
because they cannot be synthesized
within the human body from other compounds through chemical reactions,
therefore they must be periodically supplied through the food (diet). According to the World Health
Organization (WHO) and to The U.S. National Academy of Sciences (NAS), eight amino acids
are considered to be essential for human nutrition. These
essential amino acids are lysine, leucine, isoleucine, methionine,
phenylalanine, threonine, tryptophan, valine, and
(only in children) histidine and arginine.
This has been also confirmed by clinical studies performed by INRC (International Nutrition Research Center).
MAP™
(Master Amino Acid Pattern) / Product ProShape™ contains these eight essential amino acids.
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Proteins
A protein is a complex, high-molecular-weight organic compound that consists
of amino acids joined by peptide bonds. Proteins are indispensable to the structure and
function of all living cells and viruses. Many proteins are enzymes or subunits of enzymes.
Other proteins play mechanical or structural parts, such as those that form the struts and joints
of the cytoskeleton. Still more functions filled by proteins include immune response
and the storage and transport of various ligands.
In nutrition, proteins serve as the source
of amino acids for organisms that do not synthesize those amino acids natively.
Protein is an important macro nutrient to the human food, supplying the body's
needs for nitrogen and amino acids. The amount of dietary proteins needed to
satisfy these requirements may vary depending on level of physical activity, sex, age,
and medical condition.
Proteins are found in most food but are particularly concentrated in nuts,
meat, legumes, and dairy products. As it is used, much protein is converted by protein
catabolism to ammonia which, due to its toxicity, must be converted to either
urea to be excreted in urine. Protein is the major
component of muscles, tendons, enzymes, skin, hair, eyes, and other organs and processes.
The quality of protein intake is important because different
proteins supply essential amino acids in different proportions.
Protein shortage can lead to symptoms such as loss of muscle mass (proteins repair
muscle tissue), fatigue, hormonal irregularities,
insulin resistance, hair loss, and low body temperature.
Excess protein with a low NNU (Net Nitrogen Utilization) can cause problems as well,
such as impairing renal or hepatic function, bone loss due to increased acidity in the blood etc.
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