Amino acid definition
and structure -- any of a group of organic molecules that consists of a basic amino group
(-NH2), an acidic carboxyl group (-COOH), and an organic R group (or side
chain), which is unique to each. When two or more
are put together, it is called a
peptide. They play a
central roles both as building blocks of proteins and as intermediates in
metabolism. Amino acids join together to form a protein structure. Proteins are large
biomolecules that occur in every living organism. Protein is needed by the body to repair muscles, bones, organs, glands,
hair, and connective tissue. The body continually breaks down proteins into
individual amino acids and then puts the them back together again in
chains to form countless different proteins and enzymes.
Amino acids are not only cell signaling molecules but are also regulators of gene expression and the protein phosphorylation cascade. Additionally, AA are key precursors for making of hormones and low-molecular weight nitrogenous substances with each having enormous biological importance. Organisms differ considerably in their ability to synthesize an amino acid from the intermediates of metabolic pathways. Most vertebrates can form only the chemically most simple; the others must be supplied in the diet. Humans, for example, synthesize about 10 of the 20 common amino acids; these are termed nonessential amino acids.
As dietary supplement
Various amino acid supplements are available, either as individual ones, or in a number of combinations. The most popular sold over the counter are arginine, tryptophan, tyrosine, glutamine, and lysine.
Amino acid list - these are the most common found in protein
Alanine, 2-aminopropanoic acid, is non-essential. It exists as two distinct enantiomers - L-alanine and D-alanine. L-alanine is one of the 20 most commonly used in protein synthesis.
Arginine converts into nitric oxide. Arginine is considered semi-essential because although it is normally synthesized in sufficient amounts by the body, supplementation is sometimes required (for example, due to inborn errors of urea synthesis, protein malnutrition, excess ammonia production, excessive lysine intake, burns, peritoneal dialysis). Arginine is sometimes found in herbal sexual enhancement products. See also AAKG supplement which has few side effects and its safety profile is quite good.
Asparagine is one of the 20 most common.
Aspartic acid is closely related to asparagine. Some claim that aspartic acid taken as a pill or powder helps release testosterone.
Cysteine or Cystine. A more active form of cysteine is acetylcysteine, which is a powerful antioxidant.
Glutamic acid - L-Glutamic acid and gamma aminobutyric acid (GABA) are found in virtually all living organisms. In their pure form, they are powders. L-Glutamic acid is one of the major amino acids in plant and animal proteins, and is also involved in many physiologic functions. Both active ingredients act as neurotransmitters in the brain. Humans readily metabolize ingested L-glutamic acid so that concentrations in the body remain constant. Enzymes in animals and plants convert L-glutamic acid to GABA. Glutamic acid is also referred to as glutamate (the anion).
Glutamine is one of the 20 amino acids encoded by the standard genetic code. Its side chain is an amide; it is formed by replacing a side-chain hydroxyl of glutamic acid with an amine functional group.
Glycine is chemically the simplest and combines with many toxins to reduce their toxicity.
Do you know if glycine is safe for candida patients? i hear its sweet and wonder if it contains any type of sugar that will feed yeast or fungus infections.
I have no reason to suspect taking a glycine supplement will cause or aggravate candida infections, but I have not seen such studies. Some people who think they have a generalized whole body candida infection may actually have another condition that they are not aware of and blaming their symptoms on candida infection as the cause.
Is there a difference between supplementing with TMG versus glycine?
TMG has three methyl groups attached to the amino acid and has a different effect. These two supplements are not equivalent.
Histidine is one of the 20 common ones present in proteins. In humans, histidine is considered essential, but mostly only in children.
Isoleucine is essential and also a branched chain along with leucine and valine.
Leucine - A diet rich in leucine might help prevent the muscle loss that typically comes with aging. French researchers found that a leucine -supplemented diet restored a more youthful pattern of muscle-protein breakdown and synthesis to elderly rats.
Lysine is sometimes used to prevent herpes virus outbreaks although the research on this topic has shown mixed results.
Methionine and cysteine are the only sulfur-containing proteinogenic amino acids. The methionine derivative S-adenosyl methionine (SAM-e) serves as a methyl donor. Methionine plays a role in cysteine, carnitine and taurine synthesis, lecithin production, the synthesis of phosphatidylcholine and other phospholipids. Methionine is an amino acid that has antioxidant properties. Methionine acts as a methyl donor. Methionine may be converted to SAM-e, the natural depression fighter.
Phenylalanine comes in D,L Phenylalanine or L Phenylalanine. Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well.
Proline is one of the 20 used in living organisms as the building blocks of proteins. The other nineteen units are all primary amino acids, but due to the cyclic binding of the three-carbon side chain to the nitrogen of the backbone, proline lacks a primary amine group (-NH2).
Serine It is not essential to the human diet, since it can be synthesized in the body from other metabolites, including glycine.
Threonine is one of the 20. Nutritionally, in humans, threonine is essential.
Trypophan was available over the counter until banned in 1989. Early in 2000s, tryptophan supplements began to be marketed again.
Tyrosine is used to enhance alertness and mood. For information on tyrosine phenylalanine supplements. There is also another form of tyrosine called N acetyl tyrosine.
Valine is one of the 20 proteinogenic amino acids. Valine is essential and is named after the plant valerian.
Essential amino acids
Humans can produce 10 of the 20 amino acids. The others must be supplied in the food. Failure to obtain enough of even 1 of the 10, those that we cannot make, results in degradation of the body's proteins — muscle and so forth — in order to obtain the one that is needed. Unlike fat and starch, the human body does not store excess amino acids for later use—they must be present in the food every day. The essential ones include: Arginine, Histidine, Isoleucine, Leucine, lysine, Methionine, Phenylalanine, Trypophan, and Valine.
Arginine, methionine and phenylalanine are considered essential for reasons not directly related to lack of synthesis. Arginine is synthesized by mammalian cells but at a rate that is insufficient to meet the growth needs of the body and the majority that is synthesized is cleaved to form urea. Methionine is required in large amounts to produce cysteine if the latter amino acid is not adequately supplied in the diet. Similarly, phenyalanine is needed in large amounts to form tyrosine if the latter is not adequately supplied in the diet.
All the ones not listed in this section are non essential amino acids.
Less common amino acids
Acetyl L Carinitine Arginate
Carnosine is a potent antioxidant. You can buy Carnosine supplement here.
Citrulline is an amino acid. Its name is derived from citrullus, the Latin word for watermelon, from which it was first isolated. Citrulline amino acid supplement is available for sale.
GABA - gamma-amino butyric acid - is an inhibitory neurotransmitter helping nerve cells from being overly excited. This leads to relaxation. GABA is best taken on an empty stomach. GABAergic neurotransmission has been implicated in the modulation of many neural networks in forebrain, midbrain and hindbrain, as well as, in several neurological disorders.
N Acetyl L Cysteine is an amino acid supplement is available for sale.
Ornithine amino acid
PABA or Para-aminobenzoic acid is also considered a B vitamin.
Taurine is a semi essential amino acid supplement available for sale.
D and L
With the exception of taurine, GABA and glycine, most amino acids exist in either the D or L form. These forms are the mirror reverse images of each other. The L form represents the natural type found in living plants and animal tissues. The L form is used in human protein structures and is more compatible to human biochemistry than the D form. Only phenylalanine can be present in human protein structures in both the D and L forms.
Branched Chain Amino Acid
BCAAs comprise the three essential amino acids L-leucine, L-isoleucine and L-valine. These are found in proteins of all life forms. Dietary sources of the branched-chain amino acids are principally derived from animal and vegetable proteins. Vegetables and juices contain small amounts of the free amino acids, which are also found in fermented foods like yogurt and miso. Several years ago the branched-chain amino acids created some interest in the neurological research community when a pilot study indicated that amyotrophic lateral sclerosis (ALS) patients showed symptomatic improvement when given large doses of BCAAs. It was theorized that BCAAs may protect against neuronal damage from the neuroexcitatory neurotransmitter glutamate. Based on this pilot study, branched-chain amino acids received orphan drug approval for the treatment of ALS. Unfortunately, most of the follow up studies were negative, and one even suggested that BCAAs may increase mortality in those with ALS. Branched-chain amino acids are sometimes used in enteral and parenteral feedings in the management of hepatic encephalopathy. They are also occasionally used enterally and parenterally in the management of extensive burns.
They are used by body builders with the idea of producing an anabolic response, however many scientists questions the benefits of this supplementation.
Genetic disorders of branched-chain amino acid metabolism produce amino acidopathies and various forms of organic aciduria with severe clinical consequences. A metabolic block in the oxidative decarboxylation of branched-chain amino acids caused by mutations in the mitochondrial branched-chain alpha-keto acid dehydrogenase complex (BCKDC) results in Maple Syrup Urine Disease (MSUD) or branched-chain ketoaciduria.
Not only do amino acids help make neurotransmitters -- the chemicals that convey messages in the brain-- they also help produce hormones such as insulin; enzymes that activate bodily functions; and certain types of body fluids. In addition, amino acids are essential for the repair and maintenance of organs, glands, muscles, tendons, ligaments, keratin, skin, hair, and nails.
Metabolism, functions, and nutrition.
Amino Acids. 2009 May; Wu G. Department of Animal Science, Faculty of Nutrition, Texas A&M University, College Station, TX, 77843, USA.
Physiological concentrations of AA and their metabolites (e.g., nitric oxide, polyamines, glutathione, taurine, thyroid hormones, and serotonin) are required for the functions. However, elevated levels of AA and their products (e.g., ammonia and homocysteine) are harmful agents for neurological disorders, oxidative stress, and cardiovascular disease. Thus, an optimal balance among AA in the diet and circulation is crucial for whole body homeostasis. There is growing recognition that besides their role as building blocks of proteins and polypeptides, some AA regulate key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity. They are called functional AA, which include arginine, cysteine, glutamine, leucine, proline, and tryptophan. Dietary supplementation with one or a mixture of these AA may be beneficial for (1) ameliorating health problems at various stages of the life cycle (e.g., fetal growth restriction, neonatal morbidity and mortality, weaning-associated intestinal dysfunction and wasting syndrome, obesity, diabetes, cardiovascular disease, the metabolic syndrome, and infertility); (2) optimizing efficiency of metabolic transformations to enhance muscle growth, milk production, egg and meat quality and athletic performance, while preventing excess fat deposition and reducing adiposity.
The liver is the major site of gluconeogenesis, the major organ of amino acid catabolism and the only organ with a complete urea cycle. These metabolic capabilities are related, and these relationships are best exemplified by an examination of the disposal of the daily protein load. Adults, ingesting a typical Western diet, will consume approximately 100 g protein/d; the great bulk of this is metabolized by the liver. Although textbooks suggest that these amino acids are oxidized in the liver, total oxidation cannot occur within the confines of hepatic oxygen uptake and ATP homeostasis. Rather, most amino acids are oxidized only partially in the liver, with the bulk of their carbon skeleton being converted to glucose. The nitrogen is converted to urea and, to a lesser extent, to glutamine. The integration of the urea cycle with gluconeogenesis ensures that the bulk of the reducing power (NADH) required in the cytosol for gluconeogenesis can be provided by ancillary reactions of the urea cycle. Glutamate is at the center of these metabolic events for three reasons. First, through the well-described transdeamination system involving aminotransferases and glutamate dehydrogenase, glutamate plays a key catalytic role in the removal of alpha-amino nitrogen from amino acids. Second, the "glutamate family" of amino acids (arginine, ornithine, proline, histidine and glutamine) require the conversion of these amino acids to glutamate for their metabolic disposal. Third, glutamate serves as substrate for the synthesis of N-acetylglutamate, an essential allosteric activator of carbamyl phosphate synthetase I, a key regulatory enzyme in the urea cycle.
Availability of supplements
Amino acids are available either as individual tablets, capsules or pills, in an amino acid complex, or in liquid form. They can be used either by themselves or together for therapy, for instance glutamine can be used in those who have gastrointestinal damage and tyrosine to improve mood.
Nutr J. 2013 Aug 8. Development of a complex amino acid supplement, Fatigue Reviva™, for oral ingestion: initial evaluations of product concept and impact on symptoms of sub-health in a group of males. A new dietary supplement, Fatigue Reviva™, has been recently developed to address issues related to amino acid depletion following illness or in conditions of sub-health where altered amino acid homeostasis has been associated with fatigue. Complex formulations of amino acids present significant challenges due to solubility and taste constraints. This initial study sets out to provide an initial appraisal of product palatability and to gather pilot evidence for efficacy. The results indicated that Fatigue Reviva™ was palatable and that 65% of the study group reported that they felt the product had improved their health.
There are many minerals sold as amino acid chelates. Research with these forms is limited and it is difficult to say which form is better for human consumption over the long term. Here are some examples of minerals available as chelated form.
20% Zinc Chelate
2.5% Boron Chelate
15% Calcium Chelate
10% Magnesium Chelate
15% Manganese Chelate
5% Chromium Chelate
2% Cobalt Chelate
10% Copper Chelate
Amino acid side effects, safety, risk
Side effects of amino acids depends on which amino acid is being used. Some are practically harmless, whereas others, such as tyrosine, can cause anxiety, restlessness, rapid heart beat, and even heart palpitations on high doses.
Most foods that contain protein, for instance fish, meat, poultry, dairy, etc, have large amounts of amino acids. Amino acid in diet.
Body building and weight training
Amino acids are often used in body building. A soy protein powder and whey protein powder are good options to provide more protein in the diet for better muscle building. Adding creatine significantly helps in body building.
Amino acid pill
I don't see any reason to take a full complex amino acid pill since it is so much easier to take a powder and there's not much that can fit in a capsule compared to a protein powder used by the spoon or scoop. A single amino acid supplement can be taken as a pill, however a full range of amino acids are better taken in a teaspoon or tablespoon as opposed to a pill that can't hold more than a gram.
I am not aware of any amino acid supplement that improve hair in someone who has a normal diet and has no amino acid deficiency.
A Fuller list of Amino Acids
Beta -Substituted Alanines
Amino-Alkyl Carboxylic Acid (Cyclic)
Amino-Alkyl Carboxylic Acid (Linear)
Aminobutyric Acid Derivatives
Cysteine, Cystine and Derivatives
Diaminobutyric Acid Derivatives
Glutamic Acid Derivatives
Leucine and Derivatives
Ornithine, see also Ornithine alpha-ketoglutarate OKG amino acid
Pipecolic Acids, Nipecotic Acid and Isonipecotic Acid
Proline, Hydroxyproline, Thiazolidine and Derivatives
Serine and Homoserine
Statine and Analogues
Amino acid supplement questions
Is alpha gpc an amino acid?
No. Alpha GPC (L-alphaglycerylphosphosphorylcholine) is a phospholipid metabolite found concentrated in neuronal membranes.
I am confused as to the
interaction among free-form amino acids. I recently bought a “tri-amino”
formula that combines L-arginine,.
L-lysine, and L-ornithine,
supposedly to stimulate growth hormone production and muscle recovery.
However, I recently read that arginine and lysine
taken at the same time neutralize each other. Since I am interested in taking
advantage of the physiological effect of a number of free-form amino acids, such
as taurine, L-carnitine,
l-tyrosine and l-glutamine, and would like to simplify my supplementation
schedule, do you recommend combining these, or should I take them separately,
for maximum results?
The whole field of amino acid supplementation is very complicated and confusing and there is not enough human research to say much in confidence. Sometimes people focus too much on individual amino acids and miss the whole picture. For muscle building creatine and protein supplements in the form of soy or whey are the best options, and perhaps glutamine. We have not seen any convincing research that taking individual amino acids for the purpose of muscle building or health promotion is better than taking creatine or complete amino acid supplement from a protein source.
Q. I heard that aspartate
amino acid chelate supplements for example magnesium aspartate are neurotoxic
and should not be used. I believe this is because the aspartate part is
"aspartic acid" which is potentially neurotoxic. I wonder if that is true?
A. I have not seen any human research with aspartate amino acid chelate supplements that have shown neurotoxicity. If aspartic acid or aspartates are neurotoxic, it may be dose dependent, and the tiny amounts found bound to amino acids in supplement form may be too little to have any effect. Aspartates are found in the foods we eat, and thus far there is no evidence that they are harmful in the amounts people ingest in foods.
Q. I am sure that you have heard of Russel Blaylock the neuroscientist. He says that aspartic acid is an excitotoxin and causes neuronal damage. According to him it is not the aspartic acid in food that is the problem it is the free isolated form that is harmful. He was not mentioning amino acid chelate supplements but talking about aspartame, MSG and other food additives.
Amino acid supplier
We are a main manufacturer and supplier for amino acid in China. All of the amino acid products based on international standard. We have our own amino acid refine factory and unusual amino acid factory. We also have closely cooperation with Nanjing East & Shouth university for amino acid research. We wish to establish business relation with the customer in the world. Here attach with our products list for your referece: Larry Wang, Donboo Amino Acid Co., Ltd., RM C-701, Wang Jiang Building, #42 East Ren Ming Road, Nantong, 226000 Jiangsu, China
L-Form Amino Acids
L-Carnitine 50 (FEED GRADE)
L-Carnitine Fumaric Acid
L-Cysteine HCL anhydrous
L-Cysteine HCL monohydrate
L-Glutamic Acid HCL
L-Leucine (Plant origin)
L-Tyrosine (Plant origin)
D-Form Amino Acids
D-Glucosamine Sulfate (Kalium)
D-Glucosamine Sulfate (Natrium)
DL-Form Amino Acids
DL-Homecysteine Thiolactone Hydrochloride
Amino Acids Amides
Acetyl Amino Acids
Amino Acids Compound Materials
Amino Acid Chelate
Compound Amino Acid Solution (feed/food grade)
Compound Amino Acid Powder(40 80 feed/food grade)
Compound Amino Acid fertilizer
L-Arginine alpha-Ketoglutarate (2:1)
L-Ornithine alpha-Ketoglutarate (2:1) Dihydrate
Creatine alpha ketoisocaproic acid (1:2)
alpha-ketoisocaproic acid calcium salt
alpha-ketoisocaproic acid Sodium salt
L-Arginine a-ketoisocaproic acid
L-Leucine a-ketoisocaproic acid
L-Valine a-ketoisocaproic acid
L-Isoleucine a-ketoisocaproic acid
DISODIUM CREATINE PHOSPHATE 99
Aluminum Glycinate(USP23 )
Your website is wonderful. You may want to add another phenomenal product to your offerings. a PDR listed nutritional called SON Formula. It does not require a prescription, but has 44 published medical studies, 27 International Patents and 2 USA Patents to its credit. Your conservative website is a wonderful resource for people who are looking for hope, not hype, and information, not a sales pitch. What make SON Formula superior to other amino acids is its vegetable crystalline base, its 8 essential amino acid formulation, and the fact that SON Formula has a 99% Net Nitrogen Usage with only 1% catabolic waste and a 23 minute full absorption time! Compared to other amino acid supplements whose average 3 to 6 hours absorption time, 83 to 84% catabolic waste and only 16 to 17% Net Nitrogen Useage, SON Formula is the far superior supplement. Used by sports professionals to rapidly build muscle mass and the anti-aging market the most in the USA, in Europe this amino acid product is used extensively for pre and post surgery (30 days prior to surgery and 30 days post surgery at 30 pills a day), for renal failure, hepatic failure, gastrointestinal distress, Chron's disease, bed sores (I personally have seen it heal an open wound overnight), anorexia, heart problems, hypertension, the list just goes on and on.
A Medline search in April 2008 did not reveal any human studies with SON formula. At this point the burden of proof is on SON formula marketers to prove that their amino acid product is superior to and has more health benefits than soy protein powder, whey protein powder, or even eating an egg.
A naturapothic Doctor
mailed me a bag of pure white Amino Acids in powder form and asked me to mix 3
tsp. in water or juice and to take it 3 times daily. I tried it for the first
time today and it was sooo bitter I just couldn't handle the taste. I just want
to know if pure white amino acids help shrink fibriod tumors. He also sent me
some liquid herbs for the fibriod tumor but I dont know what the herbs are.
There are many types of amino acids and the information you provided is not enough for us to know whether they would be effective as a treatment for fibroid tumors.
years old student in the British university in Egypt; I've been working out
since 5 months sir. And I thought of taking some supplement of amino acids in
order to strengthen my muscles and get rid of the fatty parts in them. I bought a
supplement named "Super Amino" which has a 4800 Mg of Amino acids in it. The
company which produces it is Dymatize Nutrition. How many tablets am I supposed
to take if I'm to gain benefits and avoid harms of my "Super Amino" product? The
following is written at the back of my container, "As a dietary supplement, take
four (4) caplets three times daily. For maximum results, take between meals,
immediately after exercise, or prior to bedtime. Swallow caplets with liquid".
Since I bought this supplement sir, and I've been using only 6 caplets a day
because I'm afraid of it.
I am not familiar with Dymatize Nutrition Super Amino. I do not see the need to take such supplements since eating an egg provides all the amino acids required. If one wishes to increase muscle mass, creatine monohydrate is the best option. For additional protein one can take soy or whey protein powders.
When you take an amino acid complex
on an empty stomach do they act as "free-form" aminos or do they bond together
in your stomach and your body uses them as protein? I want to get the brain
bonuses of free-form aminos = the good mood, sleep, etc. and ifI am reading
correctly the brain bonuses only happen when the aminos are "free-form".
The body has the ability to absorb them and use them as is or convert them to proteins or other molecules. It is very difficult to predict what happens in each person. It is best to focus on each single ones alone for a specific effect rather than take a mix of several.