What is the Cell:
The cell is the basic, structural and functional unit of living beings. The word cell is of Latin origin cellula.
In biology, cells are classified into 2 large types of cells:
- eukaryotic cells: they have a cell nucleus and
- prokaryotic cells: they do not have a cell nucleus
The cell as the basic unit of all living beings, classifies organisms by the number of cells that compose it, being:
- single-celled organisms - made up of a single cell such as bacteria and protozoa, or
- multicellular organisms: with 2 or more cells, such as animals and plants.
The cell also means a small cell, cavity or hollow like cell of a monastery.
Likewise, a cell is a group that functions independently within a general organization, be it political, religious or social, such as, "Those responsible were a group of people belonging to a guerrilla cell."
In this context, cell phone is also called the prison facility where inmates are held incommunicado or the vehicle where detainees are transferred.
The photoelectric or photovoltaic cell is an electronic device that converts light energy into electrical energy through the photoelectric effect.
In general, what is related to cells or what is made up of cells is called cellular.
In America, cellular is a portable telephone that in other countries such as Spain is known as mobile.
Cell in biology
In biology, the cell is the fundamental basic unit of all living organisms. Cytology is part of biology that studies cells and their functions.
Likewise, the vital functions of living beings occur within cells and are controlled by substances that they secrete and, finally, each cell contains hereditary information which allows its transmission to the next cell generation through mitosis or meiosis, as part of the cycle. mobile.
3 vital functions for life are attributed to the cell: relationship, reproduction and nutrition.
Relationship function: Links the living being with the environment and responds to the environment.
Reproduction function: it is the process of formation of new cells from an initial cell or stem cell, through cell division that can be by mitosis or meiosis, depending on the type of cell and the stage in its cycle of life.
Nutrition function: it is the incorporation, transformation and assimilation of food and, in this way, the cell forms its own matter.
However, autotrophic cells (autotrophic nutrition) make their own organic matter using the chemical energy contained in inorganic matter, and heterotrophic cells (heterotrophic nutrition) make their own organic matter from the organic matter in the food you eat.
Depending on the type of cell, the parts that form it may differ. The smallest expression of cells, generally, are composed of 3 elements:
- Plasma membrane: cell membrane in animal cells and cell wall in plant cells.
- Cytoplasm: liquid found in the cytosol, the place where all the particular elements of each cell float (DNA, mitochondria, ribosomes, etc.).
- Cell nucleus: it is present in eukaryotic cells (with a defined cell nucleus) and is surrounded by cytoplasm.
See also Parts of the cell.
The structure, characteristics and functions of cells are beginning to be defined under the cell theory.
It is discussed around 1630 and its first 2 postulates are defined in 1839 by Matthias Jakob Shleiden and Theodor Schwann who affirm that:
- all organisms are made up of cells and,
- they derive from another preceding cell.
These foundations would later help to validate the theory of biogenesis, against the abiogenesis in which it was previously believed.
Cells are classified into different types according to the context in which they are mentioned. Some of its divisions are created according to: the definition of a cell nucleus, the kingdom of nature that the organism belongs to and its function within a being.
According to cell nucleus
In general, cells are classified into 2 large groups according to whether or not they have a defined cell nucleus:
- eukaryotic cells and,
- prokaryotic cells.
Eukaryotic cells are those that have a defined cell nucleus. This cell nucleus is found within a nuclear envelope where the integrity of the genetic material is maintained.
Cell division in organisms with eukaryotic cells occurs through mitosis and their DNA is more complex. The plasma membrane of eukaryotic cells possess sterols, carbohydrates, and their ribosomes are larger. The organisms formed by these cells are called "eukaryotes."
See also Cell nucleus.
Prokaryotic cells are those that do not have a defined nucleus, which is why the genetic material is dispersed throughout the cytoplasm.
Cell division in organisms with prokaryotic cells occurs through binary division and their DNA is not as complex as that of eukaryotic cells.
Prokaryotic cell membranes do not have carbohydrates, sterols, and ribosomes are smaller. The organisms formed by this type of cells are called "prokaryotes".
According to the kingdom of nature
The division by the type of organism to which the cell belongs, in general, is divided into 2 large groups:
- the animal cell and,
- the plant cell.
The animal cell is a type of eukaryotic cell that forms the different tissues of animals. The animal cell contains: cell envelope composed of cell membrane, cytoplasm where the cell organelles and the cell nucleus are found.
The plant cell is a type of eukaryotic cell whose nucleus is bounded by a membrane. The plant cell contains: a vacuole that stores and transports water, nutrients and waste; plastids to synthesize food and chloroplasts.
According to function
Example of cell types in the human body
According to the function of the cells, they are classified by receiving the name of the part of the organism to which they belong.
For example, somatic cells come from stem cells originated during embryonic development and undergo a process of cell proliferation and apoptosis.
The opposite of somatic cells are germ cells and from which gametes are formed.
Stem cells are located in all multicellular organisms and they have the ability to divide through mitosis and generate two identical cells and specialized cell lines in each division.
Somatic cells are those that attend the growth of tissues and organs of a living being such as skin, bones, among others. Somatic cells that mutate can be the cause of cancers, especially colon cancer.