Resumen de células y sus organelos celulares 2026 M1A14

Hello dear students, we are in one more video and we are going to talk about the different cellular elements. So let's start with the following, we are going to talk about, for example, we are going to have every cell to have an external element, in this case it would be the matic membrane or the cellular membrane. This membrane

not only will it exist in the external part of the cell and it will have very interesting functions such as guaranteeing the entry of elements to what would be the cell but it will also guarantee the output of elements from the cell but it will also have a particularity that in any case there will be some substances that will not be able to enter the cell

They will not be able to have access to the inside of the cell and this is because a characteristic of the cell membrane is that it is known as semi-permeable. That is, it means that there are elements that come out, elements that enter, but elements that cannot enter.

Normally, the elements that can enter a cell have characteristics of being highly liposoluble. If they are liposoluble, then they will have the enormous capacity to enter the cell.

So liposolubility is going to be a fundamental characteristic for the transport of elements inside the cell. However, there are going to be substances that are not going to be able to enter the cell and they are going to be those that are of characteristic that we are going to place, which are hydrosoluble. The hydrosoluble will not be able to pass or enter

with ease to what the cell itself is. The cell membrane works as a semi-permeable membrane where liposoluble substances enter and hydrosoluble substances cannot enter the interior of it, being a fundamental characteristic. Also, this allows the cell membrane to have a charge, a polarity on the surface.

This charge or polarity helps when there is a change of polarity, for example if it becomes negative, it already generates a stimulus to activate other cells, this being a help in the communication mechanism.

So this ionic exchange that the cell can suffer, changes its polarity, its external charge, because it has an internal charge and an external charge. For example, sometimes at rest it is positive outside, negative inside. Outside is the extracellular liquid and inside is the intracellular liquid.

This ionic exchange difference causes that when it is inverted and goes from negative outside and from positive inside, then what is known as an action potential is generated and the action potential generates an electrical stimulus that stimulates another cell to make its charge inversion. That at the same time will make another cell be stimulated and start that communication cycle.

So the membrane has this particularity. Now, apart from having the cell membrane, we are going to have inside the cell membrane another type of cellular organelles. We are going to have, for example, inside our cell membrane

we will have a membrane system, that is, where there will be other membranes that will wrap other structures that are inside the same cell and that help it to generate some particular function

these membrane systems obviously help that organelles that are inside those membranes cannot be combined with other elements nor the elements that they produce are affected because they are free, so for example we can have the nucleus, we can have the Golgi apparatus

we can have for example mitochondria or we can have some kind of isosome or associated element so the cell membrane also has membranes that are associated with each of the organelles that may have very particular functions associated with each of them so it not only allows an interconnection with the external medium

but also regulates the internal behavior of the different organelles that are inside the cell. So there we have that the cell membrane is going to play a very important role. Now, if we direct our look to a very particular part of, for example, cells, cells in this case like an epithelial cell, for example,

to zoom in to be able to make this relationship much better. If I have another cell here, we are going to see that this cell is going to have an interconnection with the other, especially in tissues like the epithelium, where the cells are very close to each other.

So when a cell with another one stays intimately connected, this is because a phenomenon is given that is known as desmosomes.

The desmosomes are elements that allow to connect a cell through some ligands with another establishing in this way a union, so they are joined thanks to these selectins or integrins which is the way these structures are called that allow to keep connected to some cells with others a cell provides one integrin and the other the other integrin and together they form the desmosomes in such a way that a cell provides half

and the other cell contributes the other half and that keeps these two cells together through these unions then we must also take into account that the cells can also communicate with each other thanks to what these cell membranes are but hey, we don't just find, there are not only membranes, there are not only cell membranes

that have very interesting functions that are the ones we just described we will also find other types of elements we will see it we also have in the cell a very particular organelle and this very particular organelle is the mitochondria the mitochondria which is a cell is a organelle that has the function of inside it because there is a membrane that surrounds it

The mitochondria will have the Krebs cycle inside and the ability to transform energy through oxygen. So the membrane receives the oxygen and transforms it into energy so that the cell ends up working. So a good part of the cell's energy source will be given thanks to the action of the mitochondria.

Now, this depends on the oxygen in the medium in an aerobic function mechanism, aerobic means that it depends on oxygen to function and in this way to perform the different mechanisms that are associated with the cell. This is like a motor that keeps the cell alive and active.

In fact, when there is a disorder where there is a significant decrease in, for example, blood flow and with it the levels of oxygen drop, then we will see that the cell will migrate from a function of aerobics to try to function in anaerobic form, which means in the absence of oxygen. Anaerobic.

Separating the concepts here, we realize that here there is a high oxygen potential that is being used and here there is a low oxygen potential that we are lacking and that therefore the cell has to seek to function in another way. So the mitochondria are typical elements that we find in the different cells that we have in our body.

Moving on to another element, we will also remember that we find in our cells another type of organelles. For example, we find the endoplasmic reticles associated many times to the nucleus. Here we are going to synthesize proteins.

The synthesis of proteins will help the cell to be able to reconstruct if there are damaged areas, for example, if there are some areas affected by the cell by some trauma, by some type of bacterial damage, by some type of structural damage with other cells. So those proteins that are going to be formed through the reticle

Endoplasmic will help repair that cell.

but it can also be that the cell is in a phase of development and the cell for example needs to grow so if it needs to grow a little more there will be the proteins that will be grouped to form the segment of the cell that is needed and that consequently is being developed to complete the function for which it is exposed to a certain extent

I'm going to erase a little bit here and take all the cell membranes here we have the cell and those affected areas have already been repaired and it continues to build, so this has a very important role now the nucleus

The nucleus will contain the genetic information of the cell and that will modulate its behavior. If we are going to repair, if we are going to build, that will depend on signals that the nucleus sends to the different organelles that the cell has to perform that function.

In the end, it is a collaborative work where each of those cells will have functions derived from organelles that obviously work in it. Well, I hope this short video has been useful to explain a little about the different cellular organelles. See you in a next video.