Amino Acids

Amino Acids are commonly known as the building blocks for proteins. Chemically, they are organic compounds that contain an amine group (-NH2), carboxy group (-COOH), and an R-side chain, which differentiates the different amino acids.

There are 20 (or arguably 22) proteinogenic amino acids. Proteinogenic amino acids are amino acids that code proteins. Proteinogenic amino acids are further divided into essential amino acids (these must be consumed through food), non-essential amino acids (the body can synthesize adequate levels of these on its own), and conditionally essential amino acids (these can be synthesized by the body, but may not be at adequate levels, especially when under distress).

Essential amino acids are: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine. Non-essential amino acids are: Alanine, Aspartic Acid, Asparginine, Glutamic Acid, Serine, Selenocysteine, and Pyrrolysine Conditonally essential amino acids are: Arginine, Cysteine, Glutamine, Glycine, Proline, and Tyrosine.

Some non-proteinogenic amino acids include: GABA, PABA, Cystine, Ornithine, Norvaline. There are over 140 known non-proteinogenic amino acids.