Let’s see what are the characteristics, parts, types and functions of these microscopic bodies.
The animal cell is the minimum unit of functionality that makes up living beings belonging to the category of animals, the Animalia kingdom.
Specifically, it is a type of eukaryotic cells that, combining with each other and sometimes collaborating with other forms of life (for example, bacteria that make up the intestinal flora) form functional tissues and organs, which allow the existence and survival of an animal.
In this article we will see what are the characteristics of the animal cell, as well as its main functions and specializations when forming the organism in which they live.
Characteristics of this biological unit
All animal cells belong to the eukaryotic cell taxon. These are characterized by containing all their genetic material in a structure known as the cell nucleus, and also contain different organelles separated from the rest by a membrane that covers them, unlike prokaryotic cells, which are smaller and do not present the previous characteristics ( for example, its DNA is scattered throughout the cytoplasm that fills its interior).
Furthermore, the animal cell is distinguished from the rest of eukaryotes by the fact that it organizes with others to form multicellular organisms that belong to the animal kingdom.
In turn, animals are living beings of both microscopic and macroscopic size that are characterized, among other things, by their ability to move and by presenting nerve cells, among other things. The Animalia kingdom is one of the 5 kingdoms that we find in the eukaryotic group.
Parts of the animal cell
These are the main parts and structures that make up animal cells.
The nucleus is possibly the part of the animal cell that is most important, because it not only contains an “instruction manual” on which molecules to synthesize to build and regenerate certain parts of the cell, but it is also a strategic plan for how it works. and maintenance of the organism of which the cell is a part.
In other words, the nucleus contains all the information regarding what must be done inside the cell and also outside it. This is so because within this structure, which consists of a membrane that covers it, the genetic material is protected, that is, the DNA contained in the form of a helix and folded into different chromosomes.
In this way, the nucleus acts as a filter for what enters and leaves the area where the DNA or deoxyribonucleic acid remains stored, so that it is not dispersed and lost, and trying to minimize certain molecules coming into contact with the cells. chromosomes and destabilize or alter the genetic information contained in them.
Of course, as we will see, in animal cells there is still another cellular structure that contains genetic material and that is not within the nucleus.
2. Cell membrane
The cell membrane is the outermost layer of the cell, so it covers almost the entire cell and protects all its parts equally. It consists of a set of lipids in which some proteins with specialized functions are interspersed / or embedded in these layers.
Of course, the cell membrane of animal cells, like those of any other eukaryotic living being, are not totally waterproof, but have certain entry and exit points (in the form of pores) that allow the exchange of substances with the outside. .
This increases the risk that harmful elements enter inside, but at the same time it is necessary to maintain homeostasis, the physical-chemical balance between the cell and its environment.
The cytoplasm is the substance that fills the space between the nucleus and the cell membrane. That is, it is the substance that acts as a physical support for all the internal components of the cell. Among other things, it helps to ensure that substances necessary for the animal cell to develop, or regenerate, or communicate with others, are always available within the cell.
The cytoskeleton is a set of more or less rigid filaments that have the objective of shaping the cell and keeping its parts more or less always in the same place.
In addition, they allow certain molecules to travel through their internal channels, like tubes (in fact, some components of the cytoskeleton are called “microtubules”).
Mitochondria are one of the most interesting parts of the animal cell, because they contain their own DNA, different from that of the nucleus. This structure is believed to be actually the remnant of a junction between a cell and a bacterium (the mitochondria being the bacteria inserted into the cell, fused in a symbiotic relationship).
When reproduction takes place, copies of mitochondrial DNA are also made to be passed on to offspring.
The main function of the mitochondria is the production of ATP, a molecule from which animal cells extract energy, which is why mitochondria are very important for metabolic processes.
6. Golgi apparatus
The Golgi apparatus is primarily responsible for creating molecules from raw material that comes from other parts of the animal cell. Thus, it intervenes in very diverse processes, and all have to do with the repair and production of new materials.
7. Endoplasmic reticulum
Like the Golgi apparatus, the endoplasmic reticulum is also characterized by synthesizing materials, but in this case it does so on a smaller scale. Specifically, it is especially involved in the creation of lipids with which to maintain the cell membrane.
Lysosomes are involved in the degradation of cellular components to recycle their parts and give them a better use. They are microscopic bodies that release enzymes with the ability to “dissolve” elements of the animal cell.
Types and functions
We can establish a classification of animal cells according to their functions and type of biological tissues and organs that they usually constitute when grouped together. Let’s see what these basic categories are. Of course, not all are present in all forms of animal life.
1. Epithelial cells
This type of animal cell forms superficial structures and supports the rest of the tissues. They form the skin, glands, and certain specialized tissues that cover parts of organs.
2. Conjunctive cells
These cells aim to create an interconnected structure that, beyond the skin, hold all the internal parts in place. For example, bone cells, which are included in this category, form bones, rigid structures that hold the rest of the elements in place.
3. Blood cells
These types of animal cells allow all the nutrients, vitamins and molecules necessary for life to travel through the circulatory system, on the one hand, and prevent harmful external agents from spreading through the body, on the other. Thus, their activity is linked to movement.
Included in this category are red blood cells and white blood cells, or erythrocytes and leukocytes, respectively.
4. Nerve cells
This is one of the most characteristic cell types of animal activity, as these living beings are characterized by their ability to move and process many types of information corresponding to this constant change of environment. It is a category that includes to neurons and glial cells, thanks to which nerve impulses travel through the body.
5. Muscle cells
Muscle cells form fibers with the ability to contract and relax depending on the orders that come through the nervous system.
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