The feet present chirality, since they do not coincide with their reflection.
The term chirality refers to the chiral condition . This adjective (chiral), for its part, refers to the element that cannot be superimposed with its own mirror image .
Different from reflection
Chirality, in this way, is associated with asymmetry . When an object is distinguished from its reflected image, it is chiral. On the other hand, if superposition with the mirror image is possible and a coincidence is recorded, it is something achiral .
in chemistry
In the field of chemistry , we speak of chiral molecules when their mirror image is not superimposable. Typically, this property is given by an asymmetric carbon atom, also known as a chiral carbon . These mirror images of a chiral molecule are called optical isomers or enantiomers .
Nucleic acids , carbohydrates and amino acids, among many others, are present in various medications as well as in almost all the molecules of our body, and thanks to molecular chirality it is possible for the enzymes and the corresponding substrates to interact. It is important to note that their associated chemical reactions are fundamental for life.
Today, the asymmetric carbons whose presence is considered the most frequent cause of molecular chirality are known as chiral centers . In any case, they can also be found with other names, such as stereogenic centers or stereocenters . Although this carbon is the cause of such a property, it is important that it occurs throughout the molecule. Talking in more detail about this carbon, its shape is tetrahedral and has four different groups. On the other hand, there are molecules that have a chiral center but are achiral.
With respect to visible light, we can say that it has a clear tendency to oscillate in all planes; However, it passes through a polarizing filter, it does so only in one. The chirality of the molecule serves to deflect this last plane by a certain angle. When the rotation is to the right, it is called right-handed ; The opposite direction is called levorotatory .
in physics
For physics , chirality is a phenomenon that allows us to describe how particles behave in a left-handed or right-handed reference system, also known as left-handed or right- handed, respectively. Starting from the property called spin , according to which elementary particles have an intrinsic angular momentum that does not vary, helicity can be determined, which, in certain cases, is equal to chirality.
The physical magnitude known as helicity , meanwhile, is achieved by projecting the spin in the direction of linear momentum. If the direction of the particle's motion is equal to that of its spin, then its helicity is said to be right-handed, and if they are opposite it is called left-handed helicity. In mathematical terms, helicity can be noted by the sign of such projection: positive for right-handedness and negative for left-handedness.
In the case of the gluon, the graviton (which is hypothetical) and the photon, that is, particles that have no mass, helicity is equivalent to chirality.
Molecular chirality can bend the plane of polarized light.
in geometry
The idea of chirality also appears in the field of geometry . Chirality occurs when a figure cannot be adjusted to its mirror image through translations and rotations.
It is easier to understand chirality by taking well-known examples . Shoes , in this framework, are chiral: the left shoe is a mirror image of the right shoe (and vice versa). It is evident that both shoes do not match if they are superimposed. The same goes for human hands , which cannot be superimposed and therefore there is chirality between them.