Center: definition, structure and function (with diagram) (2023)

Ocentroxom("Middle Body") is a structure found in the cells of most plants and animals.microtubulesForm and extend.

These microtubules emerge from the Microtubules Organization Center (MTOC) and are an integral part of several eukaryotic cell functions and processes throughout the life of a cell.They can be better known for their important role in the cell division process, which includesmitosis(The division of a cellular material in daughter centers)cytokinesis(The division of a complete cell in the daughters cells).

This division process is mediated bycentriolosof centers.

The centriole structure

The centers are structures that contain centrioles, which give rise to microtubules that function as the mitotic axis.This is a lot to imagine, therefore, one in terms provides a clearer idea of the physical configuration of the centers.

DuringInterface, which is the period during which a cell is not actively divided, each cell contains a centers that includes a pair of centrioles.Each of these centriles consists of nine microtubules thunderstorms in a cylindrical disposition;In other words, a single centriolo includes a total of27 microtubulesrunning from end to end.The two centrdeal are oriented at an angle straight to each other.Trillizos resemble small parallel tubes in a line.
Read more about what happens in the interface.

Also during the interface, all the basic components of a cell are replicated, including the centers and its pair of centrioles.Initially, the two centers, or centriol pairs, remain in a close physical proximity. The two centriolsmigrateof the cell that is preparing to divide into cells of two daughters.

Centers vs.Centromer:Neither the "centers" or "centriole" must be confused with theCentramero, which is the physical union between the sister chromatids of a chromosome that is being prepared to divide as part of the Mithois).

The microtubules, as observed, have several different functions in the cells, but their main objective in cell division is to serve as spindle fibers that help control and perform the separation of cellular components during the division process.

CENTROOMA AS A PART OF THE CITESQULETO

In addition to participatingmitosis, centersome plays a vital structural role in the cell, generating themicrotubulesthat form theCytoskeleton, which is what gives the cells their shape and integrity.

Although it can be tempting to imagine cells as gelatinous and fragile balloons that are little more than round containers, each cell is extremely dynamic, including its membrane, which carefully controls which substances may or may not pass inside and outside the cell.

Its objective is similar to the skeleton of your own body, which gives you your rest and general physical functions as a kind of shelf that maintains its other important physical components: its organs, muscles and tissues.

Disposition and composition of the cytoskeleton:The microtubules that form the cytoskeleton are threaded in the cytoplasm inside the cell, forming a series of devices between the cell limit and its nucleus near the center.These tubules, in turn, consist of monomeric units made of a protein calledtubulin.

This tubulin, like many proteins in nature, comes in a variety of subtypes;The most common found in microtubules are:

Only in the presence of a centers, these spontaneous monomers are formed in the microtubules, in the same way, perhaps, since eggs, sugar and chocolate are formed only in cookies in the presence of a staff kitchen.

In addition, proteins calledDineinesmiCinesinasParticipating in mitosis;This helps to guide the extremes of the microtubules to their right places throughout the chromosomes that will soon be divided, which are aligned along the metaphase plate.

Importance of the centers:It is not yet known how exactly the duplication of the centers occurs during the interface.In addition, it is remarkable that, although cenossomas and centrioles appear in most plant cells,Mitosis can occur in plants in the absence of these structuresIn fact, in some animal cells, mythosis can even work when centriols have been deliberately destroyed, but this generally results in an unusual number of replication errors.

Therefore, it is believed thatCenosomas help transmit a degree of controlThroughout the process, and biochemists strive to elucidate the mechanisms of this because they are probably important inthe genesis and progression of cancersand other disorders that depend on replication and cell division.

Role of the Centers Division

Cell division is a crucial component of cell biology.The centers play an important role in this process.

Remember that the two single center centriles are oriented at an angle straight to each other, which means that the microtubules in these centriols will be organized in one of the two mutually perpendicular directions.It should also be made that the two centers in a cell also the unhappy division is found at the opposite ends of the interface cell.

An implication of this geometry is that when mythosis spindle fibers begin to form,extender(the "pole") Of the cell towards its center, where the cell division is more evident, andThey also extend or "fans"in a variety of addresses of each own centers.

Try to keep your fists held slightly separated and open it slowly as your newly visible fingers extend;This offers a general image of what develops in centers as mythosis continues.

Mitosis itself includes four phases (sometimes listed like five).In order, they are:

Some sources also includePrometafaseBetween prophase and metaphase.To the extent that mythosis begins, the microtubules that grow from the nascent mitotic axis in each pole move towards the center of the cell, where the replicated chromosomes arranged in pairs are aligned along the so -called so -called soMetaphase plate(An invisible line along which the spin -off of the nucleus occurs).

These variant ends of the spindle fibers end in one of the three places: in theCinetocoreOf each chromosomal pair, which is the structure in which the chromosomes really separate;in the arms of the chromosomes;and in the cytoplasm itself on the other side of the cell, closer to the opposite centers than to the point of origin of these fibers.

Spindle fibers in operation:The range of anchor points of the ends of the spindle fibers attests to the elegance and complexity of the mitotic process.It is a kind of "war cable", but it must be extremely well coordinated, so that the "pass" division in the exact environment of all chromosomes pairs to ensure thatEach daughter cell receives exactly a chromosome from each pair.

The spindle fibers, therefore, make some "thrust", as well as much of "throwing" to ensure that cell division is not only strong, but needs.The microtubules participate only in the division of the nucleus, but also participate in the division of the entire cell(that is, cytokinesia) and the reyglusion of each new daughter cell in its own cell membrane.

One way to imagine all this: cells have no muscles, but microtubules are the closest to the cellular components they receive.

Centrioan replication

As indicated, cell centers are replicated during the interface, the relatively long part of the cell cycle between mitotic divisions.conservative,Which means that the two centriles of the daughter formed are not totally identical, as would be the case in a conservative process.semi -conservative.

While the exact mechanism of the replication of the aumosome during theS fase (synthesis phase)From the cell interface it must still be completely understood, scientists have realized that when a centriole is divided,One of the resulting centrals maintains the characteristics of the "mother"and can generate operational microtubules.

This centriole has "stem cells" properties, while the other, the "daughter", becomes totally different.Each new daughter cell, as expected, contains a centriole mother and a daughter of Centriola in each pair.During the following interfing, this centriole will be divided to create two pairs of central centers.

Centriols in different structures:The subtle differences of function between the centrioles reference angle in each pair are evident when, for example, the Centriolo mother joins inside the cell plasma membrane to form a structure calledBasal body.This body is usually part of a tab length, or several microtubules, which is not mobile;That is, it does not move.

Someeyelash(The plural of "cilio")Flagelos("Scourge" singular) that move, often increasing the entire cells, while in other cases, they serve as miniature brooms of a type that cleanses the rubble of the scourge region.

Although biologists have a lot to learn about the precise dynamics of the centers, cancer provides a window for what goes wrong with the centers in abnormal cell division.Researchers have observed, for example, thatCancer cells generally contain an unusual number of centersInstead of one or two expected, and certain cancer medications (for example, taxol and vincristine) exert their effects, interfering with microtubules assembly.

Paper in tab formation

A scourge is a variety of microtubules that allow locomotion, as in the case of asperm cell.A scourge originates in a single basal body on the internal surface of the plasma membrane.Therefore, a sperm cell contains a single pair of centrioles.

Because the final destination of a sperm cell is to merge with aeggthatThe centriole includes instructions and components necessary for the division process.

Some organisms have eyelashes in certain cells.This includes some of the cells of its own respiratory tract.epithelium(Surface cells; its skin is a kind of epithelium) that aligns the lungs forms several connected basal bodies, which is really lightning and, therefore, protects the inside of the lungs.