The cell and its structural characteristic
The cell was discovered by the English scientist Robert Hooke in 1665 who, when observing with a microscope manufactured by it, saw fine corks of tiny structures gave a cell name this word you come from the Latin cell that means small room reason whyI call her of this name is because I reminded them of the cells in which the monks lived at that time, but in reality what he observed were dead plant cells. Some time later Dutch scientist and inventor Anton Van Leeuwenhoek in 1670 observed and discovered living cells in the water to which I call them animals since for him these were small animals, although they were bacteria as we know today, he also contributed to the discovery of thesterilization by saying that sperm entered the ovules giving fertilization.
In 1824 Rene Duthet. In 1838 two great German scientists discovered what we now called cell theory the first was the German botanist Matthias Schleiden who said that all plants are composed of cells, the second was the German zoologist Theodor Schwann who said the animals were alsoformed by cells and from here the origin of cell theory began .In 1850 another Rudolf Virchow German doctor contributed the progress of these research and affirmed that cells come from other cells, that is, they arise from a pre -existing. (Campos, 2002)
The cell is the smallest unit we find in living beings, they are very tiny that we cannot see them at first glance we can only observe them through a microscope, their size is measured in micrometer or micra, these can be unicellular, that is, if theorganisms are formed by a single cell and multicellular if they are formed by more cells.
Cell types
Prokaryotic cells
They are very small unicellular organisms that measure around 1 UM, they are the simplest in living organisms, these cells lack the nucleus their structures are: bacterial capsule, cell wall, plasma membrane, cytoplasm, genetic material, ribosomes, flagella, fimbriaand Pilis
Eukaryotic cells
They are those cells in which the genetic material is wrapped by a nuclear membrane that in turn make up a cell nucleus and have different organelles, are divided into animal and plant cell. (Manson & Jones, 2003)
Structural characteristics of cells
The size of the cells is measured in microns, mostly almost all are small range from 1 um to 100 um some larger one is because they are made up of many cells, but in reality there is no large cell, also alsoThey have very variable forms and can be elliptical, flattened, globed, crashed, fusiform, rounded and prismatic.
Regardless of the type of cell that is all have the following structures.
- Hereditary genetic material: contain deoxyribonucleic acid (DNA), replicates it and transcribes RNA.
- Cytoplasm: It is the internal medium of the cell has the material that is within the cell especially ribosomes, also as water, salts and organic molecules.
- Cell membrane: it is a cell protection regulates the substances that enter and leave it, it also obtains nutrients and eliminates waste. (Audesirk, Audesirk, & Bruce, 2003)
Functional characteristics of cells
- Nutrition: The cells feed on organic matter, that is, they take energy that are found on the outside of the cell and make it nutrients in order to fulfill each of its functions and these in turn the metabolism that is very importantin each living being.
- Growth: Cells are divided into other cells, that is, as in one of the postulates of cell theory it is said that a cell arises from another pre -existing is very true because through that the growth of them arises, and each cellDaughter and equal to the cell that reproduced it, there is no change because DNA is the same, this is called cell duplication better known as the mythosis process.
- Differentiation: There is a process called cell differentiation in which each cell after reproduction is taking new forms and sizes of agreement by which they differ from each other by its structure.
- Signaling: The cells interact with each other through neurotransmitters and respond to both physical and chemical stimuli of the external or internal environment of the same.
- EVOLUTION: All living beings thus evolve the cells since it is the smallest living organism also with the passing of time these evolve since in the reproduction stage they can be identical to the stem cells, but when time passes these can goChanging structures and sizes, this is agreed to the adaptation they have had even positive or negative.
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