Essential and Nonessential Amino Acids | Table with Complete List

Amino acids are the molecules that make up the proteins.

Proteins are the building blocks of the body.

In the body, proteins comprise more than 50% of total body mass.

While the rests are carbohydrates and fats.

The proteins from food & other supplements we consume get broken down into amino acids by the action of enzymes in the digestive system.

These are then absorbed into the blood and supplied to the whole body.

They help the body in building the required protein in the cell by a process known as a translation of mRNA.

What are Essential and Nonessential Amino Acids

The amino acids are scientifically differentiated as essential and nonessential amino acids.

Every amino acid has a carboxylic moiety and an amino group.

Essential amino acids are those which can’t be synthesized inside the body of both humans and animals. They are synthesized only by plants and microbes. Hence one is required to get these essential amino-acids through diet.

Nonessential amino acids: These are the amino acids that are formed inside the body. So, one need not worry if he is getting these amino-acids from external source or diet.

List of  Essential amino acids

Number	Amino acid’s Name
1 (essential in preterm infants)	Arginine
2	Histidine
3	Isoleucine
4	Leucine
5	Lysine
6	Methionine
7	Phenyalanine
8	Threonine
9	Tryptophan
10	Valine

List of non-essential amino acids

Number	Name of Amino acid
1	Alanine
2	Aspargine
3	Aspartic Acid
4	Cysteine
5	Cystine
6	Glutamic acid
7	Glutamine
8	Glycine
9	Hydroxyproline
10	Proline
11	Serine
12	Tyrosine
13 (Non-essential in adults)	Arginine

Of the above amino acids, there are small distinctions.

Aromatic amino acids: These are the ones that have aromatic groups in their molecule. See phenylalanine structure in the above diagram.

Aromatic rings are the ring-like carbon molecules that are double bond and unsaturated in nature.

Examples for such amino acids include

Phenylalanine, tyrosine, tryptophan.

Aliphatic amino acids: These are ones that have aliphatic groups like -CH2- in between carboxylic and an amine moiety. They are the ones excluding aromatic amino acids from the above list of both essential and non-essential ones.

Similarly, some of them have special functional groups unlike others

Example: Sulfur-containing ones; Methionine, cysteine.

Hydroxyl groups containing ones are serine and threonine, contain aliphatic.

The amino acids are zwitterions i.e. they possess both positive and negative charges on the same molecule.

Amino-acids are needed for various biochemical reactions. For this, they are either naturally synthesized or obtained from the diet. Some of the reactions where they are needed include in the formation of proteins, enzymes, different hormones, etc.

In times of starvation, the amino acids are synthesized from stored carbohydrates and fats.