The cell is the basic anatomical and indispensable unit present in every living being that fulfills 3 fundamental functions: they absorb nutrients from food, reproduce sexually and asexually, and collect information from the environment in the form of signals or stimuli. One of the types is the prokaryotic cell, which is known to be a unicellular organism that belongs to the Prokaryota empire and has its genetic material scattered throughout the cytoplasm.
Some of the most outstanding characteristics of the prokaryotic cell are the following:
- Nutrition is autotrophic (makes its own organic matter) or heterotrophic (it feeds on another organism that it parasitizes).
- It reproduces asexually (one only gives rise to other beings) or parasexually (transfer of genetic material without meiosis).
The bacterium is known as a unicellular microorganism with a very small size of between 0.5 and 5 µm . It is one of the most abundant living beings on planet Earth and exists in the most diverse environments as it withstands very extreme conditions.
It is characterized by not having a nucleus or, in general, internal membranous organelles, although it does have a cell wall composed of peptidoglycan or murein.
Some of the bacteria live inside other organisms and are known as endosymbionts, taking as an example the bacterial flora that is located in the gastrointestinal tract.
examples of bacteria
E -coli is a gram-negative bacterium that lives in the intestines of humans and warm-blooded animals. Some of the strains have acquired genes that have enabled them to cause an infection.
Clostridium botulinum is found in soil and water , and is capable of creating spores that survive on poorly preserved food. Therefore, when someone eats said food, they are ingesting said bacteria and that causes serious poisoning.
L.acidophilus is a beneficial bacterium for humans by collaborating in digestion, increasing the bioavailability of nutrients and helping to eliminate pathogenic microorganisms in the stomach and intestine.
Example 2: archaea
The archaea, also known as archaea, is a unicellular prokaryotic microorganism that does not require sunlight for the process of photosynthesis. It is characterized by living in places with extreme conditions such as hot springs and saline.
examples of archaea
The haloarchea is an aerobic microorganism that is found in saturated or almost saturated salt water, which is why it is also called halophilic archaea. For its growth it needs more than 2.0 M NaCl, which is an ionic compound with a white crystal appearance.
The methanogenic archaea is a prokaryotic microorganism that obtains energy through the production of natural gas and methane (CH 4 ).
It generally inhabits areas where oxygen is spent , for example, sediments in swamps and marshes. It should also be noted that it is in the digestive tract of rabbits, ruminants (suborder of artiodactyl mammals) and horses.