What are the differences between essential and nonessential amino acids?

Basis of differentiation

Essential amino acids

Nonessential amino acids

Definition 

Are amino acids that cannot be synthesized by the human body and can only be obtained from the daily diet

Are amino acids that can be synthesized by the human body and need not be taken in through diet 

Number of Amino Acids

9 of the 20 amino acids are considered essential

11 of the 20 amino acids are considered non-essential

Sources

Can be obtained through various foods such as egg, quinoa, chicken, soy, meat and vegetable protein

Are produced within the body from other amino acids and a few other components

Function 

- Form precursor molecules for the formation of neurotransmitters in the brain

- Helps in building and repairing muscle tissues 

- Removal of toxins

-  Promotes brain function

- Integral in synthesis of RBC and WBC in the body

Probability of deficiency 

Highly probability of essential amino acid deficiency as they are acquired through food

Generally low probability of nonessential amino acid deficiency, but can still occur due to illness or starvation 

Also known as

Indispensable amino acids

Dispensable amino acids

Examples 

- Histidine

- Tryptophan

- Lysine

- Phenylalanine 

- Valine

- Asparagine

- Glutamine

- Tyrosine

- Cysteine

- Alanine