What are non-essential amino acids? List, Uses, and Functions

Last updated on May 24th, 2023 at 05:33 pm

5 minutes read.     

Amino acids are biological organic molecules that are the building blocks of all proteins, including the most abundant fibrous proteins in the skin, such as keratins, collagen, and elastin in the human body and other animals. There are 20 amino acids used for protein synthesis in the human body.

Out of the twenty amino acids, eleven are regarded as non-essential amino acids, meaning your body can make (synthesize) them on its own, you don’t have to get them from your diet.

Then the remaining nine are said to be essential amino acids, meaning your body cannot make them on its own but demand them for healthy living. Therefore you must obtain them from food sources. Learn more about essential amino acids.

Chains of amino acids create protein in the human body, other animals, and plants.

It is important you understand the functions of non-essential amino acids in your body and how you can maintain them for healthy living. That’s why I wrote this article.  Feel free to jump to any of the topics that catch your eye.

• What’s a non-essential amino acid?
• Uses and Functions
• How to maintain the non-essential amino acids in your body?
• Synthesis
• Amino acid supplement
• Conclusion

What are Non-essential amino acids?

Non-essential amino acids are those eleven amino acids out of the twenty amino acids needed by the body to synthesize a protein that your body can produce on its own.

However, the use of the word “non-essential” does not mean that they’re not important or are not required for the formation of proteins in the body, only that you don’t have to eat the food that contains them for your body to have it.

Therefore they’re not essential in the diet hence the name “non-essential amino acids”.

But do you know the catch in this?

Your body demands essential amino acids to be able to produce (synthesize) non-essential amino acids to enable it to perfume its function well.

That’s why when you don’t feed on proteinous food (essential amino acid Rich diet) for a couple of days or weeks you will begin to experience all kinds of negative side effects which can risk your health if overlooked.

Find out food rich in essential amino in my previous article.

Essential amino acids include:

Phenylalanine, Valine, Tryptophan, Threonine, Leucine

Isoleucine, Methionine, Histidine, Lysine.  

More so, some amino acids are regarded as conditional amino acids because they are mainly needed by the body during times of illness and stress.

Conditional amino acids include arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine.

Put together here, the 20 amino acids include:

Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine ,Histidine, Isoleucine, leucine, Lysine, Methionine, Phenylalanine, Proline, Serine, Threonine ,Tryptophan, Tyrosine, Valine,

Eleven Non Essential Amino acids include:

1. Alanine,

2. Arginine,

3. Asparagine,

4. Aspartic acid,

5. Cysteine,

6. Glutamic acid,

7. Glutamine,

8. Glycine,

9. Proline,

10. Serine, and

11. Tyrosine

Uses and Functions of Nonessential amino Acids in the body

Let’s look at the role of each of the non-essential amino acids in detail.

1. Alanine

Alanine is a non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination.

It is involved in sugar and acid metabolism increases immunity and provides energy for muscle tissue, the brain, and the central nervous system.

2. Arginine

Arginine is a conditionally/semi-essential amino acid that is required during periods of maximal growth, severe stress, and injury.

Arginine is a substrate for protein synthesis but also modulates cellular biochemical functions via conversion to a number of biologically active compounds.

Arginine has many effects on the body that include modulation of immune function, wound healing, hormone secretion, vascular tone, insulin sensitivity, and endothelial function.  Arginine mediates its effects via nitric oxide-independent and dependent pathways.

3. Asparagine

Asparagine helps to break down toxic ammonia within cells, is important for protein modification, and is needed for making a certain molecule that transmits signals in the brain (a neurotransmitter).

4. Aspartic acid

Aspartic acid is a physiological amino acid occurring principally in the pituitary gland and testes and has a role in the regulation of the release and synthesis of luteinizing hormone and testosterone in humans.

Luteinizing hormone plays an important role in sexual development and functioning. In women, the Luteinizing hormone helps control the menstrual cycle. It also triggers the release of an egg from the ovary.

Luteinizing hormone spurs ovulation and helps with the hormone production needed to support pregnancy.

Your provider may order a test to check your Luteinizing hormone levels if you have fertility issues or irregular menstruation.

In men, the luteinizing hormone stimulates Leydig cells in the testes to produce testosterone, which acts locally to support sperm production.

5. Cysteine

Cysteine acts as a precursor for the synthesis of glutathione, which is an important antioxidant. The reduced form of glutathione plays a fundamental role in the defense of the organism against damage caused by oxidative stress.

6. Glutamic acid

Glutamic acid is necessary for the synthesis of key molecules, such as glutathione and polyglutamated folate cofactors.

It plays a major role in signaling. Within the central nervous system, glutamate is the major excitatory neurotransmitter, and its product is GABA, the major inhibitory neurotransmitter.

Gamma(γ)-Aminobutyric acid, or GABA, is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system.

 Its principal role is reducing neuronal excitability throughout the nervous system. GABA is sold as a dietary supplement in many countries.

7. Glutamine

Glutamine stimulates protein synthesis and reduces ubiquitin-dependent proteolysis in the enterocyte since this amino acid reduces ubiquitin gene expression.

Glutamine can increase the gene expression of the arginine-succinate synthase enzyme in Caco-2 cells (human colon epithelial-line cell).

8. Glycine

Glycine acts as a neurotransmitter in the central nervous system and it has many roles such as antioxidant, anti-inflammatory, cryoprotective, and immunomodulatory in peripheral and nervous tissues.

Glycine is the smallest amino acid with a single carbon molecule attached to an amino and a carboxyl group.

Its small size helps it to function as a flexible link in proteins and allows for the formation of helices, an extracellular signaling molecule, recognition sites on cell membranes and enzymes, a modifier of molecular activity via conjugation and glycine extension of hormone precursors

9. Proline

Proline plays important roles in protein synthesis and structure, metabolism (particularly the synthesis of arginine, polyamines, and glutamate via pyrroline-5-carboxylate), and nutrition, as well as wound healing, antioxidative reactions, and immune responses.

On a per-gram basis, proline plus hydroxyproline are most abundant in collagen and milk proteins, and requirements of proline for whole-body protein synthesis are the greatest among all amino acids.

Therefore, physiological needs for proline are particularly high during the life cycle.

10. Serine

Serine plays an essential role in a broad range of cellular functions including protein synthesis, neurotransmission, folate and methionine cycles, and synthesis of sphingolipids, phospholipids, and Sulphur containing amino acids.

11. Tyrosine

Tyrosine is synthesized in the body from phenylalanine (an essential amino acid). 

In the body, tyrosine plays a role in protein synthesis and serves as a precursor for the synthesis of catecholamines, thyroid hormones, and melanin.

It is considered a non-essential amino acid; however, in patients with phenylketonuria who lack phenylalanine hydroxylase and cannot convert phenylalanine into tyrosine, it is considered an essential nutrient. Such patients can obtain it through tyrosine supplements.

How to maintain the non-essential amino acids in your body? 

For you to maintain the non-essential amino acid in your body, you must feed on food that is very rich in essential amino acids because your body uses the essential amino acid obtained from that food to produce the non-essential amino acid which together is used to synthesize a protein that builds a healthy body.

Synthesis of Nonessential amino acid

How do non-essential amino acids made in the body?

Synthesis of the nonessential amino acids depends mainly on the formation of appropriate alpha (α)-keto acids, which are the precursors of the respective amino acids.

For example, pyruvic acid, which is formed in large quantities during the glycolytic breakdown of glucose, is the keto acid precursor of the amino acid alanine.

Then, by the process of transamination, an amino radical is transferred to the alpha (α)-keto acid, and the keto oxygen is transferred to the donor of the amino radical.

Amino acid supplement

Some essential and non-essential amino acids have been developed in the form of dietary supplements. Taking amino acids supplements can actually help you maintain and meet up with the required amount by your body.

However, as long as you can obtain essential amino from your diet which in turn is used by the body to make the non-essential, it may be irrelevant to consume them in the form of a supplement.

But if you choose to consume amino acid supplements in any condition please keep to the dosage recommended to avoid overconsumption which may lead to negative side effects.

If any side effects occur discontinue and inform your medical professional.

Some amino acids you can find in the form of supplements include glycine, glutamine, phenylalanine, tyrosine, and many more.

Conclusion

Amino acids are molecules containing an amine group, a carboxylic acid group, and a side chain that is specific to each amino acid. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen.

A protein is a large biological polymer synthesized from amino acids, which are carboxylic acids containing an alpha (α)-amino group.

Your body needs about twenty amino acids to synthesize the protein it requires for optimal biological function.

Out of the twenty amino acids, eleven are called non-essential amino acids meaning your body can make them on its own so you don’t necessarily need to get it from the diet.

The functions of nonessential amino acids range from protein synthesis, increasing the immune, providing energy for metabolism, moderate cellular biochemical function, breakdown toxic compounds within the cells, transmitting signals to the brain(neurotransmitters), regulating the release and synthesis of sex and growth hormone, protect against free radicals (antioxidant), wound healing, and skin pigmentation.  

The remaining nine are called essential meaning they cannot be made from your body, therefore, you must obtain them from food sources because your body demands them to enable it to produce the non-essential and in combination build protein in the body.

It’s important you start incorporating food rich in essential amino to your diet to enable your body to produce and maintain the non-essential amino acids which all together make proteins that build a healthy body.

I hope you get the value worth your time. I appreciate the time you spend with me. Leave a comment if you like this post. So tell me, do you think is necessary for you to maintain the nonessential amino acid in your body? Feel free to share your thought with me in the comment below.

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