There are generally two cell types: the prokaryotic cell and the eukaryotic cell.
Eukaryotic cells are cells found in your body. In general, eukaryotic cells have a nucleus and other organelles, such as mitochondria and chloroplasts (plant cells only), that give them their special powers. This includes e.g. B. aerobic cell respiration (mitochondria) or photosynthesis (chloroplasts), with the help of which eukaryotic cells can gain a lot of energy in the form of ATP.
Prokaryotic cells are the cells that are found everywhere, such as in the sea, in the ground, or in the air. They lack a nucleus and other organelles, but have a protein-based cell wall that protects them. Compared to eukaryotes, prokaryotes are significantly more resistant to extreme environmental conditions.
Prokaryotic Cell – Definition
Prokaryotes are known for their ability to quickly adapt to new environmental conditions. This is due on the one hand to horizontal gene transfer and on the other hand to the fact that they can multiply quickly through cell division. In general, prokaryotes are also smaller than eukaryotes. On average, they are only 1–2 μm in size.
Did you know that the DNA of a prokaryotic cell lies freely in the cytoplasm?
Figure 1: Schematic representation of a bacterium
Eukaryotic Cell – Definition
There are significantly larger eukaryotic cells such. B. the human egg cell. This is about 100 micrometers, i.e. 1 mm, in size.
Belong to the eukaryotes people, Animals such as Plant and Mushrooms.
formation of eukaryotes
Nowadays scientists go from the endosymbiont theory to explain the origin of eukaryotes. This theory describes that plastids and mitochondria were taken up by precursors of eukaryotic cells by endocytosis. This created a symbiosis between the cells, with the ingested prokaryotic cell providing nutrients to the outer cell, while the outer cell provides protection and constant living conditions.
A comparison of prokaryotes and eukaryotes
Prokaryotes and eukaryotes differ in their structure as well as in gene expression, reproduction and protein biosynthesis.
Construction
The following table represents cell organelles or cell components found in eukaryotic and/or in prokaryotic cells.
A prokaryotic cell is “simple”, meaning that it has no compartments as in eukaryotic cells. Therefore, the DNA is free in the cytoplasm in the form of a DNA coil (nucleoid) and DNA plasmids.
Plant cells and prokaryotic cells have a cell wall that protects the interior of the cell from external influences and provides stability.
The flagellum, which is only found in prokaryotic cells, is used for locomotion.
Gene regulation, reproduction and protein biosynthesis
Cell division in prokaryotes is different from that in eukaryotes. Mitosis is not possible in prokaryotes, so a prokaryotic cell divides as follows: first its DNA is duplicated and the copy of the DNA becomes part of the new cell. In this case, two identical daughter cells or clones are formed. In contrast, mitosis does not produce identical clones.
Comparing prokaryotes and eukaryotes—summary
According to the endosymbiont theory A eukaryotic cell is said to have developed from a prokaryotic cell. However, the two cell types appear to have evolved differently as they differ in several factors.
In the table below you will find an overview of the general differences between prokaryotes and eukaryotes.
Prokaryotes and Eukaryotes – The Most Important
- Prokaryotes are living things that have cells without a nucleus and cell organelles. Procytes include bacteria and archaea.
- Procytes are able to divide much faster than eucytes. This is because the division of their cells occurs in a simple form:
- division of DNA
- division of the cell
- Two identical daughter cells are formed.
- Eukaryotes are living beings that have cells with a nucleus. Eucytes are about animals, fungi and plants.
- The cell division of a eukaryotic cell takes about 2 to 50 hours.