Centriole Definition and Meaning
The scientific Latin word centriolum, which can be translated as “small center”, passed into the German language and then came to our language as centriole. The concept refers to an organelle of cells that is made up of microtubules.
It should be remembered that cells are the fundamental units of a living being that have the capacity for independent reproduction. The functional and structural units of cells are called organelles: the centriole, or centriole, is one of these organelles.
As we said above, centrioles are made up of microtubules, which are hollow filaments made up of proteins. Its function is to promote the movement of the cell through flagella and cilia (cellular structures in the form of appendages that look like microscopic hairs) and organize its cytoskeleton.
Microtubules are structures of cells grouped in a tubular shape, with an outer diameter of 25 nm and an inner diameter of 12 nm. Regarding its length, it can be a few nanometers or a few micrometers. They arise in specific organizing centers and travel across the entire surface of the cytoplasm.
Regarding the cytoskeleton, we can say that it is a network of proteins that provides internal support in eukaryotic cells, is responsible for the organization of internal structures and also participates in the phenomena of division, traffic and transport of cells.
The centriole must go through a replication process to give rise to the creation of several procentrioles and, in this way, participate in the formation of cilia in the so-called differentiation cells, which start from one lineage to acquire the functions and morphology of another.
When the centrioles are positioned in pairs and perpendicular to each other, they form a diplosome. These diplosomes can be surrounded by a protein mass, forming a centrosome. The centrosomes, therefore, are two paired centrioles (diplosomes) that are embedded in the proteins that are around them.
It is important to highlight, on the other hand, that the centrioles play a role in the cell division process. Each of the centrioles of the mother cell passes to one of the daughter cells, acting as a pattern or model for the development of the new centriole. The location of the nucleus and the rest of the spatial organization of the cell in question depend on the position of the centrioles in the cell.
The structure of the centriole is very particular: each one consists of nine triplets of microtubules, which are located in such a way that their appearance is that of a circle. The one closest to the center is called microtubule A and has thirteen protofilaments (which is why it is considered to be “complete”).
Two other microtubules are attached to A: B, with which it shares three protofilaments, and C, the one furthest from the center and with which it also has three protofilaments in common. The protein that binds the triplets is called nexin.
This concept belongs to the field of molecular biology, which has the purpose of studying the processes whose development takes place in living organisms from the perspective of the molecule. At present, it is understood that the objective of molecular biology is to offer an explanation for the phenomena of life based on their macromolecular properties.
Within this branch of biology, the following two are the macromolecules that mainly represent its object of study:
* nucleic acids, a group in which deoxyribonucleic acid stands out, commonly known by its acronym DNA;
* proteins, which in a living organism are its active agents.