Glutamine
Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, polar amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet. It is encoded by the codons CAA and CAG.
Magnesium in biology
Mg is the fourth-most-abundant metal ion in cells (per moles) and the most abundant free divalent cation — as a result, it is deeply and intrinsically woven into cellular metabolism. Indeed, Mg-dependent enzymes appear in virtually every metabolic pathway: Specific binding of Mg to biological membranes is frequently observed, Mg is also used as a signalling molecule, and much of nucleic acid biochemistry requires Mg, including all reactions that require release of energy from ATP. In nucleotides, the triple-phosphate moiety of the compound is invariably stabilized by association with Mg in all enzymatic processes.