Another category of chelate is the amino acid chelates. There are 20 amino acids. Amino acids are the building blocks of protein. Amino acids are moderately strong chelating agents. Once inside the plant the mineral is released and the left over amino acids that formed the protective shell are used by the plant as a source of water soluble nitrogen. After all, amino acids are building blocks in cell machinery. Everything is used, nothing is lost. Amino acid chelates are generally systemic in the plant meaning they move and travel to where they are needed. They can do this because amino acids are recognized by the plant as building blocks and are used in nearly every tissue in the plant. Glycine chelates (also known as glycinates) are a subset of amino acid chelates. Glycine is the smallest amino acid and it is often used as a chelating agent. Since glycine is small it makes a small final product that passes through leaf pores (stomates) more easily than other larger molecules, thus enhancing plant uptake.