Difference Between Essential and Non-essential Amino Acids

The key difference between essential and non-essential amino acids is that essential amino acids cannot be synthesized by the body, whereas non-essential amino acids can be synthesized by the body.

Amino acids are the building blocks or precursors of proteins. As its name implies, amino acid contains an amino group (-NH2) and an acidic carboxyl group (-COOH). With these two groups, an additional hydrogen and a functional side chain (R group) are bonded to a central carbon atom. The nature of this R group determines the unique characteristics and the chemistry of the amino acid; thus, resulting in various proteins. Proteins are the most diversified group of macromolecules, both chemically and functionally. There are 21 different amino acids linked via peptide bonds to make various proteins. All of them are essential for every organism.

CONTENTS

1. Overview and Key Difference
2. What are Essential Amino Acids
3. What are Non-essential Amino Acids
4. Side by Side Comparison – Essential vs Non-essential Amino Acids in Tabular Format
5. Summary

What are Essential Amino Acids?

Most plants and microorganisms are capable of synthesizing all 20 amino acids on their own from glucose or CO2 or NH3-. During the process of evolution, mammals, including humans, have lost the ability to synthesize the carbon skeleton for several of the amino acids. Therefore, it is essential to obtain these particular amino acids through the diet. Those amino acids that cannot be synthesized in the body to meet the demand required by the body are known as ‘essential amino acids’.

There are 9 essential amino acids the human body requires: phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, lysine, and leucine. Since animal flesh is a complete source of essential amino acids, non-vegetarians need not be too concerned about a balanced diet, but those who do not eat animal products should consider about the essential amino acids because the body cannot synthesize certain basic proteins without these amino acids.

What are Non-Essential Amino Acids?

Non-essential amino acids are the amino acids our body can produce itself. Even though we can obtain these amino acids through our diet, the human body can still synthesize these particular amino acids.

Figure 01: Amino Acids

The non-essential amino acids include 12 amino acids. Those are alanine, arginine, cysteine, tyrosine, glutamine, glutamate, glycine, histidine, serine, asparagine, aspartate, and proline. Although non-essential amino acids are readily available in the human body, we can also obtain them from food like nuts, grains, meats, fruits and vegetables.

What is the Difference Between Essential and Non-essential Amino Acids?

The key difference between essential and non-essential amino acids is that the human body cannot synthesize Essential amino acids, whereas the human body can synthesize non- essential amino acids. Therefore, one must obtain essential amino acids through the diet. However, it is not necessary to obtain non-essential amino acids as the body can synthesize them on their own. In addition, essential amino acids are usually available in animal products, while non-essential amino acids are available in both animal and plant products. So, we can consider this too as a difference between essential and non-essential amino acids.

Summary – Essential vs Non-essential Amino Acids

Amino acids are the building blocks of proteins. There are two types of them as essential and nonessential amino acids. The human body cannot synthesize essential amino acids while the human body can synthesize non-essential amino acids. Thus, this is the key difference between essential and non-essential amino acids.

Reference:

1. “Essential Amino Acids: Definition, Benefits and Food Sources.” Healthline, Healthline Media, Available here.

Image Courtesy:

1. “Amino Acids” By Dancojocari – Own work, Also, created with Adobe Illustrator.iThe source code of this SVG is valid (CC BY-SA 3.0) via Commons Wikimedia

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