Though it is sometimes found in alpha helices, it is more common in triple helical molecules, such as collagen.  
Like GABA and glutamic acid, this nonessential amino acid can inhibit neurotransmitter signals in the central nervous system.  Though it is sometimes found in alpha helices, it is more common in triple helical molecules, such as collagen.  It is the only amino acid which is not optically active, due to its lack of a chiral center.  For 10 points-name this amino acid whose possession of a single hydrogen as its R-component makes it the simplest amino acid.
Like GABA and glutamic acid, this nonessential amino acid can inhibit neurotransmitter signals in the central nervous system.  
glycine