All biological tissues contain amino acids. All amino acids except glycine (the simplest one) are optically active, having a stereocenter at their α-C atom. This means that the amino acid can have two different configurations, "D" or "L" which are mirror images of each other.
All biological tissues include amino acids. All amino acids except glycine (the simplest one) are optically active, possessing a stereocenter at their α-C atom. This implies that the amino acid can have two distinct configurations, "D" or "L," which are mirror images of each other.