There are 20 different amino acids each consisting of a backbone to which a side group is attached. The amino acid backbone is the same for all amino acids, but the side group varies. It is side group that makes each amino acid unique.Most naturally occurring amino acids are of the L-configurations, although D-amino acids are not uncommon in some microorganisms.
The presence of a D-amino acid oxidase in mammalian tissue, however, suggests that the D-forms may play some yet unrecognized role in mammalian protein metabolism.
Nine of amino acids are called essential amino acids, because human body cannot make them and must get them though diet. The body can manufacture the remaining 11 amino acids, called nonessential amino acids.
When amino acid backbones joined end to end, a protein forms. The bonds that from between adjoining amino acids are called peptide bonds. Proteins often contain from 35 to several hundred or more amino acids.
Amino acids are not stored in the body in any appreciable amounts; therefore, proper nutrition requires eating enough protein just about every day to meet the body’s needs for essential amino acid.
Amino Acids
