Amino acids, peptides and proteins are important constituents of food.
They supply the required building blocks for protein biosynthesis.
The amino acids are the fundamentals units of protein structure. All
amino acids contain at least one amino group (-NH2) in the alpha
position and one carboxyl, and all (except Glycine) contain an
asymmetric carbon atom. For this reason, they may exist as isomers.
The term amino acid might mean any molecule containing both an
amino group and any type of acid group; however, the term is almost
always used to refer to an carboxylic acid. The simplest acid is
aminoacetic acid, called glycine.
Amino acids play major role in regulating multiple processes related to
gene expression, including modulation of the function of the proteins
that mediate messenger RNA (mRNA) translation.
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.
Based on their nutritional/physiological roles, amino acids can be differentiated as:
• Essential amino acids: Valine, leucine, isoleucine, phenylalanine,
tryptophan, methionine, threonine, histidine (essential for infants),
lysine and arginine (“semi-essential”).
• Nonessential amino acids: Glycine, alanine, proline, serine, cysteine,
tyrosine, asparagine, glutamine, aspartic acid and glutamic acid.
Amino acids are utilized in formation of protein. If amino acids are
deficient, then protein synthesis does not occur. As a result protein
deficiency disease may occur. It is necessary to take balanced diet
containing all essential amino acids.
Amino acids – fundamental units of protein
