In this paper we describe the phenomenon of chirality with mathematical notions. The concept of chirality emerged from the need to describe some phenomena in which a special shape of symmetry appears in the mirror. Moleculele importante în procesele biologice sunt ori “de dreapta” , sau “de stânga”. These two forms what they appear in the phenomenon of chirality are difficult to distinguish if only the metric value is considered. To distinguish chiral values there is a need more than a metric, space orientation must be introduced to define reflexes and mirrored images, it is necessary to position in given space in coordinates. Changing the chirality of the base which means the transition from a left to a right one, or vice versa, is done by mirroring that involves changing the meaning of one versors from the bases.