Amino Acid
- Amino acids are the building blocks of proteins. They play an important role in a metabolic pathway, gene expression , building muscles, causing chemical reactions
within the body, transporting nutrients, preventing illness, and cell signal transduction - An amino acid is a type of organic compound that consists of a carboxyl functional group (-COOH) and an amine functional group (-NH2), as well as a side chain (R group) that is specific to every amino acids
- Protein catalyzes the majority of chemical reactions in cells. They provide many structural elements to a cell, and they help bind cells to tissues.
- Amino acids are different from each other based on the specific chemical structure of their R group.
- In the human body, 20 amino acids make proteins.
- Nine of these amino acids are considered essential (they must be taken in through the diet), while five are considered nonessential because the human body can make them. The remaining six protein-forming amino acids are conditional, which are necessary for certain stages of life or in certain conditions of disease.
- The essential amino acids are tryptophan, phenylalanine, methionine, isoleucine, leucine, Histidine, lysine, threonine, and valine.
- The nonessential amino acids are alanine, aspartic acid, glutamic acid, Asparagine, and serine.
- Conditional amino acids include arginine, glutamine, cysteine, proline, glycine, and tyrosine.
- Some authorities recognize the 21st amino acid, selenocysteine, which is derived from serine during protein biosynthesis.
- Deficiency of amino acids can result in depression, lowered mental alertness, digestive issues, decreased immunity, slowed growth in children, fertility problems, and other health issues.
Classification of amino acids
The 20 standard amino acids found in the protein structure are divided into seven separate groups.
1.Aliphatic amino acids
2.Hydroxyl group-containing amino acids
3.Sulfur-containing amino acids
4.Acidic amino acids and their amides
5.Basic amino acids
6.Aromatic amino acids
7.Imino acids
Aliphatic amino acids
These are mono-amino mono-carboxylic acids. This group consists of the most common amino acids.
Glycine:
- Glycine is a small, simple amino acid. Its R – group is hydrogen.
- Glycine is a nonessential amino acid.
- It is an allosteric inhibitor of glutathione syntheses.
Abundant In:
It is found in tendons, skin, connective tissue, ligaments, cartilage, and bones. In addition, glycine is found a lot in gelatin, a substance made from collagen. Gelatin is usually used as a gelling agent in the production and cooking of food.
Benefits:
- Glycine is used to help with treating schizophrenia, stroke, benign prostatic hyperplasia (BPH), and some abnormally inherited metabolic disorders.
- It is used to protect the liver from the harmful effects of certain drugs used after organ transplants and the harmful effects of alcohol.
- Glycerin is involved in transmitting chemical signals to the Brain.
- Glycine is found in large amounts of collagen. Collagen is a structural protein, which promotes elasticity for the skin.
- Glycine can be applied to cure some wounds and ulcers in the legs.
- Glycine is used in treating ischemic stroke.
Alanine:
Alanine is a nonessential amino acid. Β-Alanine is found in pantothenic acid. D-Alanine: it is a component of the bacterial cell wall.
Abundant In:
Alanine is found in many foods such as soy, meat, nuts, dairy products, and whole grains.
Benefits:
- Alanine is used to break down vitamin B-6 and tryptophan.
- It is a source of energy for the muscles and the central nervous system.
- It strengthens the immune system and helps the body use sugar.
- Alpha-alanine is used for hypoglycemia (low blood sugar), liver disease, and diarrhea-related dehydration.
- Valine:
- Valine is an essential amino acid.
- Valine has an aliphatic hydrophobic isopropyl (3Carbon) side chain.
Abundant In:
Valine is found mostly in the inner part of the globular protein (helps determine the 3-dimensional structure). Valine is obtained from meat, cheese, soy, fish, and vegetables.
Benefits:
- Valine (a glycogenic amino acid) maintains mental vigor, emotional calm, and muscle coordination.
- Valine supplements are used for tissue repair, muscle growth, and energy.
- Valine also increases growth hormone production and lowers elevated blood sugar levels.
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Leucine:
Leucine is an essential amino acid
Leucine has an aliphatic hydrophobic isopropyl (4Carbon) side chain.
Abundant In:
Leucine is found in milk, soy, and beans.
Benefits:
- Leucine can help heal skin and bones.
- It can help with muscle growth and lean body mass.
- Leucine can increase the production of HGH (human growth hormone).
- This can help control blood sugar.
- Leucine can help muscles recover after heavy use.
Isoleucine:
- Isoleucine is an essential amino acid.
- Isoleucine has 4Carbon, an aliphatic hydrophobic isopropyl side chain.
Abundant In:
Isoleucine is found in especially high amounts in meats, cheese, fish, eggs, most seeds and nuts, chickens, and lentils.
Benefits:
- Isoleucine is involved in muscle metabolism and is largely found in muscle tissue.
- Isoleucine is also important for hemoglobin production, energy regulation, and immune function.
- Isoleucine is the oxygen-carrying pigment inside red blood cells.
Hydroxyl group-containing amino acids (-OH)
Serine:
Serine is a nonessential amino acid. 
Serine has an alcohol group, is a site for phosphorylation of many proteins.
Abundant In:
Serine is an essential amino acid that is supplied from food or produced by the body from several metabolites (including glycine). Serine is found in eggs, meat, fish (especially shellfish), nuts (specifically almonds, walnuts, and peanuts), soybeans, and lentils.
Benefits:
- D-serine is found to help memory and cognitive function, Parkinson’s disease, schizophrenia, and many other conditions.
- L-serine helps in Lou Gehrig’s disease (amyotrophic lateral sclerosis or ALS).
- It also helps to improve sleep.
- Serine participates in the biosynthesis of purines and pyrimidines, so it is important in metabolism.
It is a precursor to several amino acids, including glycine and cysteine, and tryptophan in bacteria.
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Threonine:
- Threonine is an essential amino acid.
- Its alcohol side group is a target for the phosphorylation of proteins.
Abundant In:
Threonine is abundant in meats, fish, eggs, and dairy products,
Benefits:
- Threonine is used to help with various diseases of the nervous system, including multiple sclerosis, spinal spasticity, amyotrophic lateral sclerosis (Lou Gehrig’s disease, ALS), and familial spastic paraparesis.
- It supports digestive health.
- It boosts the immune system.
- It may improve muscle contractions.
- It supports muscle and bone strength.
Sulfur-containing amino acids:
Cysteine:
- Cysteine is a nonessential amino acid.
- Cysteine is another essential amino acid containing sulfur; it is formed from the concentration of two molecules.
Abundant In:
Cysteine is one of the most minor amounts of amino acids, yet it is often found as a highly preserved residue within functional (regulatory, catalytic, or binding) sites in proteins. The body can synthesize cysteine from methane and other building blocks. Cysteine, the amino acid that makes up NAC, is found in most protein-rich foods.
Benefits:
- Cysteine can play a role in the average hair growth rate.
- Cysteine can also help reduce the effects of aging on the skin.
- This can help keep the skin healthy after surgery or burns and protect the skin from radiation injury.
- Cysteine can help burn fat and build muscle mass.
Methionine:
- Methionine is an essential amino acid.
- Methionine is coded by AUG in the genetic code.
- It is called the start codon. Methionine is the first amino acid used to make a protein chain.
Abundant In:
It’s abundant in meat, seafood, egg whites, and certain nuts and seeds.
Benefits:
- Methionine is an antioxidant. It can help protect the body from damage caused by ionizing radiation.
- It can detoxify harmful substances such as heavy metals in the body.
- It can also prevent liver damage from acetaminophen poisoning.
- It may help reduce the risk of Colorectal Cancer
- Can Lower Tremors in Parkinson’s Patients
- Builds Bone Strength.
Acidic amino acids and their amides:
Aspartic acid:
- Aspartic acid is a nonessential amino acid
- It is capable of forming ionic bonds and is involved in chemical reactions.
Abundance:
They are abundant in oysters, luncheon meats, sausage meat, oat flakes, avocado, asparagus, young sugarcane, and molasses from sugar beets.
Benefits:
- D-aspartic acid is commonly found in the pituitary gland and testes and is not used for protein synthesis. It is involved in the release, regulation, and synthesis of testosterone and luteinizing hormone (LH).
- D-aspartic acid (natural amino acid) can increase low testosterone levels.
- Research shows that it works primarily by increasing the levels of pituitary stimulant hormone and luteinizing hormone, which in turn stimulates the Leydig cells to produce more testosterone.
- Aspartic acid improves stamina.
Glutamic acid:
Glutamic acid is a nonessential amino acid.
Abundant In:
It is the most abundant amino acid. All meats, poultry, fish, eggs, dairy products, and combo are excellent sources of glutamic acid. Some plant foods rich in protein also serve as sources. 30% to 35% of gluten (which is mostly protein in wheat) is glutamic acid.
Benefits:
- Glutamate is the most common stimulant neurotransmitter in the central nervous system.
- Glutamate treats childhood behavioral issues and personality
- Glutamate help treats muscular dystrophy and epilepsy.
- Glutamate treats intellectual disorders.
Asparagine
Asparagine is a nonessential amino acid.
Abundance:
The most abundant types of post-translational modification are asparagine-linked protein glycosylation. Asparagine was first isolated from asparagus juice in 1806. Aspergillus was the first amino acid isolated.
Asparagine is widespread in our food supply – it is present in some plant-based foods such as whole grains, nuts and seeds, soy, and some vegetables (yes, asparagus too). It is also found in large quantities in dairy products, eggs, fish, seafood, beef, and poultry.
Benefits:
- Asparagine is needed for the development and function of the Brain. Asparagine also plays a vital role in the synthesis of ammonia,
- Asparagine is essential for the production of proteins, enzymes, and muscle tissue in the body.
Glutamine
- Glutamine is a nonessential amino acid.
- It is an essential compound in the transamination reaction.
Abundance:
The intramuscular glutamine content is equal to 50–60 to the total free amino acids found in skeletal muscle tissue. Approximately 80% of glutamine is found in skeletal muscle in the body, and this concentration of Asparagine is 30 times higher than recorded on human plasma.
Benefits:
- Glutamine is a source of energy for the intestines and immune cells.
- It helps maintain a barrier between the intestines and the rest of your body and helps with the proper development of intestinal cells.
- Glutamine can help, especially during times of stress.
Basic amino acids:
Lysine
- Lysine is an essential amino acid.
- Lysine is strongly polar.
Abundance:
Lysine is most abundant in meat, dairy, and fish, fruit, vegetables, and legumes. Typically, industrially prepared lysine is added to livestock feed to overcome the limited abundance of lysine.
Lysine from a sugar base, industrially prepared by microbial fermentation. Genetic engineering research is actively pursuing bacterial strain to improve production efficiency and allow lysine to form from other substrates.
Benefits:
- Lysine helps the body in absorbing calcium, zinc, and iron.
- It promotes collagen growth
- It helps to produce enzymes and antibodies
- It can Promote Wound Healing
Arginine
- Arginine is intermediate in the urea cycle and a precursor to nitric oxide.
- Arginine contains the guanidino group and is monocarboxylic acid.
Abundance:
Arginine is abundant in many different foods, and your body can make it.
Arginine is found in red meat, poultry, beans, most protein-rich foods, including fish, soy, whole grains, and dairy products. L–arginine can, as a supplement, be used topically and orally.
Benefits:
Arginine is used to treat conditions of the heart and blood vessels, including congestive heart failure (CHF), chest pain, hypertension. It helps in correcting inborn errors of urea synthesis.
Histidine
- Histidine is a semi-essential amino acid.
- Histidine contains an imidazole ring.
Abundance:
Histidine is abundant in fish and red meat, but its content differs amongst species of fish, from fish rich with Histidine (dark muscle fish) to fish poor with Histidine (white muscle fish).
Benefits:
Histidine is an amino acid that is a building block of proteins. People use Histidine as a medicine. Due to kidney failure or kidney dialysis, Histidine is used for Rheumatoid arthritis, Allergic diseases, Ulcers, and anemia.
Aromatic amino acids
Phenylalanine
- Phenylalanine is an essential amino acid.
- Phenylalanine contains a benzene ring.
Abundance:
Phenylalanine is found naturally in mammals’ breast milk. It is used in the manufacture of food products and is sold as a nutritional supplement for its renowned analgesic and antidepressant effects. Phenylalanine is a direct precursor to the neuromodulator phenethylamine (a commonly used dietary supplement).
The primary dietary sources of L-phenylalanine include meat, fish, eggs, cheese, and milk.
Benefits:
Phenylalanine is used for skin diseases called vitiligo, ADHD (attention deficit-hyperactivity disorder), depression, osteoarthritis, chronic pain, rheumatoid arthritis, alcohol withdrawal symptoms, and Parkinson’s disease.
Tyrosine
- Tyrosine is a nonessential amino acid.
- The hydroxyl group of tyrosine is a site for phosphorylation in proteins, and it gives a slight polarity to the side chain.
Abundance:
Tyrosine is found in milk proteins, casein, and other dairy products (such as cheese). Tyrosine is also present in meat and red wine. Because tyrosine is a nonessential amino acid, it is produced by the body when ingested in insufficient amounts.
Benefits:
Tyrosine is a joint dietary supplement. It is used to improve:
- alertness,
- attention
- It produces essential brain chemicals that help nerve cells communicate and also control mood
- Despite these benefits, tyrosine supplementation can interact with side effects and medications.
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Tryptophan
- Tryptophan is an essential amino acid.
- Tryptophan contains indole rings.
Abundance:
Tryptophan is abundant in most dietary proteins or protein-based foods. It is specifically found in oats, dried dates, milk, red meat, chocolate, yogurt, cottage cheese, eggs, fish, sunflower seeds, poultry, sesame, buckwheat, gram, almonds, pumpkin seeds, spirulina, and peanuts.
Uses:
The naturally occurring tryptophan helps to produce serotonin, which has many health benefits, including helping to promote better sleep, relieving anxiety and depression, increasing emotional well-being. This includes helping to manage pain tolerance.
Imino acids
In the intestinal brush border membrane, the IMINO system is unique for imino acids, for example, pipecolic acid, proline, and hydroxyproline. It is present in the jejunum along with the ileum. The transport process is Na+-dependent. In addition to Na+, Cl− also plays a compulsory part in the catalytic cycle.