The cell is the smallest unit of life , and is a fundamental component to define us as living beings. Since its size is so small, it was not discovered until the invention of the microscope.
It is from the 19th and 20th century that the cell theory was developed, which explains that the cell is the structural unit of living beings and states that all living beings are made up of one or more cells. It is also considered a functional unit, as it carries out all vital functions (nutrition, relationship and reproduction). Likewise, the cell is the genetic unit, which contains the hereditary material and all come from another pre-existing cell.
In this article you will find the main differences between prokaryotic and eukaryotic cells explained.
Different types of cells
Therefore, a cell can be defined as the structural, functional and genetic unit of all living beings, and can be classified in different ways. Mainly in prokaryotic (or prokaryotes) and eukaryotic (or eukaryotes) cells. The latter, in turn, can be classified into animal and plant cells, although protozoa, algae and fungi are also eukaryotic organisms .
The two major groups of cells (prokaryotes and eukaryotes) have similarities and differences. The former are unicellular organisms, which lack a defined or true cell nucleus and in which the DNA is dispersed by the cytoplasm . These are the bacteria. Eukaryotes are organisms composed of cells that possess a true nucleus, delimited within a double lipid layer, and with an organized cytoplasm.
Similarities between prokaryotic and eukaryotic cells
While prokaryotic and eukaryotic cells are different in many ways, they also have some similarities. Both contain genetic material, i.e. DNA. They have a cell membrane that covers them. Their basic chemical structures are similar , as both are composed of carbohydrates, proteins, nucleic acid, minerals, fats and vitamins.
Both prokaryotic and eukaryotic cells contain the ribosomes, which produce proteins . Both types of cells regulate the flow of nutrients and waste matter into and out of the cells. They also reproduce, although in different ways. They need energy to survive, contain cytoplasm inside the cells and a cytoskeleton. Both kinds of cells have a lipid bilayer, known as the plasma membrane, which forms the boundary between the inner and outer side of the cell.
Differences between prokaryotic and eukaryotic cells
There are also some differences between prokaryotic cells and eukaryotic cells. Scientists believe that eukaryotic cells evolved from prokaryotic cells.
But what are these differences? In the following lines we explain them to you.
While eukaryotic cells have a well-defined nucleus, prokaryotes do not. Within the eukaryotic nucleus is stored the genetic information .
It is estimated that prokaryotic cells have their origin around 3700 million years, whereas eukaryotic cells are estimated to be 2000 million years old.
Prokaryotic cells are smaller : 0.1-5.0µm in diameter. The largest eukaryotes : 10-100µm in diameter.
4. Cellular organization
Prokaryotic cells are usually unicellular, while multicellular eukaryotes.
5. Genetic material
The genetic material of eukaryotes is stored in the nucleus; however, in the case of prokaryotic cells, it is dispersed throughout the cytoplasm. DNA from prokaryotic cells does not associate with histones.
6. Composition of the plasma membrane
In eukaryotic cells, the plasma membranes contain sterols . In the case of prokaryotic cells, only in mycoplasmas.
7. Form of genetic material
In prokaryotic cells, the DNA is circular. However, in eukaryotic cells, the DNA is linear and, as discussed above, is associated with histone proteins.
8. Number of chromosomes
Prokaryotic cells have only one chromosome. However, eukaryotic cells have multiple chromosomes .
9. Plasma membrane
In prokaryotic cells the plasma membrane is composed of peptidoglycan or murein. In the case of eukaryotes, it is made up of phospholipids.
The prokaryotic cells have an inner matrix with non-membranous organelles . The prokaryotic cells have membranous organelles in the cytoplasm (e.g. Golgi apparatus).
Reproduction in prokaryotic cells occurs by asexual reproduction, by binary fission. In contrast, in eukaryotic cells reproduction occurs by mitosis and meiosis.
12. Living Organisms
Prokaryotic cells are bacteria , while prokaryotic cells are part of animals, plants, fungi, protozoa and algae.
Differences between animal and plant cells
Within the different types of eukaryotic cells we can find animal and plant cells, which despite showing some similarities, are also different in some aspects.
As for the shared characteristics , both have a well-defined nucleus, where they house the DNA. They also perform similar production processes, including mitosis and meiosis. Cellular respiration is necessary to obtain energy, and they share some cellular components (Golgi apparatus, endoplasmic reticulum, ribosomes, etc.)
In reference to the differences, plant cells store energy in the form of starch , while animal cells do so in the form of glycogen. The former are usually larger than the latter, and usually have a rectangular shape. Although both have cell membranes, the cell wall is only present in plant cells, algae, archaea and fungi. Plant cells are capable of synthesizing all the essential amino acids, which is not the case with animal cells.