Glutamine
In human blood, glutamine is the most abundant free amino acid.
Amino sugar
In organic chemistry, an amino sugar (or more technically a 2-amino-2-deoxysugar) is a sugar molecule in which a hydroxyl group has been replaced with an amine group. More than 60 amino sugars are known, with one of the most abundant being "N"-Acetyl--glucosamine, which is the main component of chitin.