What are amino acids?
Amino acids are a simple organic compound containing both a carboxyl (-COOH) and an amino (-NH2) group. About 500 naturally occurring amino acids are known, though 25 amino acids that link together into polypeptide chains to form proteins are necessary for all life.
Proteins are complex molecules that are used in the normal functioning of the human body. They are essential for the structure, function, and regulation of the body’s tissues and organs. Proteins are made up of hundreds of smaller units called amino acids that are attached to one another by peptide bonds, forming a long chain.
Proteins are broken down into amino acids, which are used to help the body with various processes namely building muscle and regulating immune function. Amino acids are divided into 3 different groups namely essential, semi-essential, and non-essential.
Essential Amino Acids
Nine amino acids are classified as essential amino acids, namely Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine. Essential amino acids are not created by the human body and need to be supplemented in the form of diet.
Functions of essential amino acids in our body
Histidine: Histidine amino acid produces histamine. Histamine is a neurotransmitter that is essential for immune response, digestion, sexual function, and sleep-wake cycles. It is used in maintaining the myelin sheath, a protective barrier that surrounds nerve cells.
Isoleucine: Isoleucine amino acid helps in muscle metabolism and is concentrated in muscle tissues. It is important for immune function, hemoglobin production, and energy regulation.
Leucine: Leucine amino acid is used in protein synthesis and muscle repair. It regulates blood sugar levels, stimulates wound healing, and produces growth hormones.
Lysine: Lysine amino acid is used in protein synthesis, hormone and enzyme production, and absorption of calcium, which is important for energy production, immune function, and the production of collagen and elastin.
Methionine: Methionine amino acid is used for metabolism and detoxification, which is important for tissue growth and the absorption of zinc and selenium minerals, which are vital to our health.
Phenylalanine: Phenylalanine amino acid is a precursor for neurotransmitters namely tyrosine, dopamine, epinephrine, and norepinephrine, which are used in the structure and function of proteins and enzymes and the production of other amino acids
Threonine: Threonine amino acid is a principal part of structural proteins namely collagen and elastin, which are components of the skin and connective tissue. It also is used for fat metabolism and immune function.
Tryptophan: Tryptophan amino acid is needed to maintain proper nitrogen balance and is a precursor to serotonin, a neurotransmitter that regulates appetite, sleep, and mood. Tryptophan amino acid is also associated with causing drowsiness.
Valine: Valine amino acid helps stimulate muscle growth and regeneration and is used in energy production.
Semi-essential Amino Acids
Histidine and Arginine are semi-essential amino acids, which are required by growing children in the form of diet but are not essential for the adults.
Non-essential Amino Acids
The amino acids which are produced by the human body are called the non-essential amino acids namely Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine, and Tyrosine.
Uses of non-essential amino acids
Alanine: Alanine amino acid is produced by other amino acids like pyruvate and leucine, valine and isoleucine. It is also known as L-Alanine and a more dense form called Beta Alanine. Beta Alanine is used in sports, as it is a performance improver. Alanine along with Glutamine helps maintain Amino Acid Metabolism in the body. It helps in maintaining glucose levels in the body and helps in the prevention of insulin shocks and low sugar levels in the blood.
Arginine: Arginine amino acid is also known as L-Arginine. Arginine changes to Nitric Oxide in the human body and serves as a powerful vasodilator. Arginine is used in the healing of wounds, detoxification of kidneys, immune and hormone maintenance, and artery dilation.
Asparagine: Asparagine amino acid is known as the first amino acid to be isolated from its source. Asparagine is known for synthesis of glycoproteins in the human body and is synthesized by the liver. Asparagine is used in transporting nitrogen inside the body, as well as cell building capability. It is the most important amino acid for neuron development. It can improve stamina in athletes.
Aspartic acid: Aspartate amino acid is commonly known as Aspartic Acid and it is a negatively charged polar amino acid. It is synthesized by the liver in the human body. Aspartate is a combination of iron, copper, magnesium, and zinc to produce dietary supplements. Aspartate is used to increase the solubility of minerals such as iron, copper, magnesium, and zinc. It is beneficial in stimulating NMDA receptors.
Cysteine: Cysteine amino acid is widely used by the human body for various important functions. In supplements, it is usually in the form of N-acetyl-L-cysteine (NAC). The body converts it into cysteine and then into glutathione, which is a powerful antioxidant. N-acetyl-L-cysteine (NAC) is administered when a person has acetaminophen overdose. It is used in the treatment of chronic bronchitis and COPD. N-acetyl-L-cysteine (NAC) with nitroglycerin is used to treat angina/chest pain with patients suffering from coronary artery disease (CAD). N-acetyl-L-cysteine (NAC) is also used to treat Acute Respiratory Distress Syndrome (ARDS) which is developed post lung injury and can prevent disease growth.
Glutamic acid: Glutamate amino acid is also referred to as Glutamic acid. Glutamate is widely used as an ingredient known as MSG (monosodium glutamate). Glutamate is used as a very powerful neurotransmitter. Excess concentration of Glutamate is highly toxic. Glutamate is the major mediator of signal transduction in humans, as well as mammals in the central nervous system (CNS). It plays the role of memory vitalization, cognition, and learning. It acts as a neurotransmitter. Glutamate is mainly present in the brain at good concentrations. It plays a crucial role in brain metabolism. Glutamic acid is used in the treatment of schizophrenia. It helps in reversing the deficiency of the syndrome.
Glutamine: Glutamine amino acid is one of the widely known amino acids. Glutamine is commonly known as L-Glutamine. It is present in high amounts in the skeleton and Glutamine contains Nitrogen and is also known as nitrogen carrier. Glutamine is consumed after a workout by athletes, as it aids in faster muscle recovery. Glutamine helps in the prevention of infection with patients suffering from burns. Intravenous administration of Glutamine helps in killing bacteria post surgery and also helps to restore the immune system.
Glycine: Glycine amino acid is the smallest amino acid with respect to its structure. Glycine is manufactured by the body and a normal meal contains around 2 grams of Glycine in it. Glycine is combined with glutamate and other drugs in the treatment of schizophrenia. Glycine helps in the prevention of ischemic stroke. Ischemic stroke is the most common type of brain stroke and it is caused by the blockage of a blood vessel in the brain. Oral administration of Glycine during the stroke helps limit the damage. Glycine is used in creams to treat leg ulcers.
Proline: Proline amino acid is known as L-proline. It helps in the formation of collagen. Collagen is very smooth and flexible tissue that helps in holding the bones together. It helps in the prevention of arteriosclerosis. Arteriosclerosis is thickening or hardening of arteries, which leads to various heart diseases. Proline helps in the breakup of fat in the wall of arteries and thereby decreasing the chances of heart blockage.
Serine: Serine amino acid is also known as L-serine. It is synthesized by the body from glycine and threonine. Serine is used by the body to produce tryptophan. Tryptophan is used to synthesize serotonin (the mood hormone). Deficiency in the levels of serotonin and tryptophan leads to symptoms like anxiety, confusion, insomnia, and depression. Serine is used in fat metabolism. It also helps in proper functioning of RNA and DNA. It helps in muscle formation and immune maintenance. Serine is used in the treatment of chronic fatigue syndrome. Chronic fatigue syndrome is a disorder characterized by extreme fatigue that cannot be explained by any underlying medical condition. The fatigue may worsen with physical or mental activity but does not improve with rest. Serine is used in the treatment of fibromyalgia. Fibromyalgia is a disorder characterized by musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues.
Tyrosine: Tyrosine amino acid is also known as L-Tyrosine. Tyrosine is one of the most important amino acids. Tyrosine is used for management of bodily functions and makes it one of the most important amino acid. Iron-rich food is the source of tyrosine. Tyrosine is used in the prevention of brain damage. Phenylketonuria is a rare genetic disorder where the body is unable to produce Phenylalanine, which can lead to brain damage. A supplement of Tyrosine helps in the production of Phenylalanine, which helps in the treatment of brain damage. Tyrosine supplementation is used for stress relief. Tyrosine restores neurotransmitter hormones such as dopamine, norepinephrine, and epinephrine, and with the release of these hormones, Tyrosine helps in stress relief. L-Tyrosine also helps in focus and energy. Excess levels of Tyrosine may also destabilize the production of thyroid hormones.
Which foods contain these essential amino acids?
- Lean meat, poultry, and fish: Lean meat such as chicken and turkey and seafood such as fish are high in protein and low on fat. Seafood is a high source of omega-3 fatty acids, which is heart healthy and can reduce joint stiffness and inflammation.
- Eggs: One medium egg contains around 6 grams of protein and is one of the highly rich sources of essential amino acids.
- Dairy products: Dairy products are another high protein and calcium-rich source, which can be consumed on a daily basis.
- Beans and legumes: Such as lentils and chickpeas. Beans and pulses are great protein sources. They are also a good source of iron and fiber.
- Nuts and seeds: Nuts and seeds are also high in protein. Around 50 pistachio nuts provide 6 grams of protein, plus sodium and potassium, and the electrolytes lost in sweat during exercise. It can also be consumed as a quick breakfast.
- Soy products in the form of tofu. People allergic to dairy products have an alternate food in the form of soy products. Foods in the form of tofu also help in lowering cholesterol and prevents heart diseases.
How much amino acids should you consume?
A daily quantity of around 0.8-1 gm of protein/kg of body weight is recommended. For weightlifters and strength athletes 1.4 – 2 gm of protein/ kg of body weight is recommended daily; with a recommendation of 1.2-1.6 gm of protein/ kg of body weight daily for endurance athletes. After exercise, protein is particularly important since muscles need it to recover and grow. A portion of protein (15-25 grams) is recommended within 30 minutes of exercise when your muscles are particularly receptive to protein synthesis. If you are keen on building muscles and/or a regular to the gym, you might want to up the intake of amino acids for better muscle growth.
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