Prokaryotes are the unicellular organism which does not have any membrane bounded structures including the basic called nucleus. They do no possess any cellular regions as well.
With the prokaryotic cells lacking almost many organelles, some of the examples of prokaryotic cell are the bacteria, mycoplasma and the blue green algae. Among these, bacteria are the most common ones.
Some more common examples of prokaryotic cells are-
- Cyanobacteria
- Archaea
- Bacillus anthracis
- Bacillus careus
- Streptomyces soil bacterium
- Escherichia coli bacteria
- Streotpcoccus bacteria
- Lactobacillus acidophilus
- Streptococcus pyogenes
- Sulfolobus acidocaldarius archaebacterium
All living being fall into two groups wither eukaryotes or the prokaryotes. The determination of the group of an organism is done based on the cellular structure.
The prokaryotic cells are indeed small and have simple cells that measure around 0.1 to 5 μm in diameter. Inside the prokaryotic cells, the DNA bundles are in stored all together inside a region called as nucleoid.
Cyanobacteria
They are the aquatic and photosynthetic in nature and are most in common form of bacteria. Cyanobacteria resemble bacteria in their structure.
They are the oxygenic phototrophs and example of prokaryotic cell which have in them a green pigment known as the chlorophyll. Along with a green augments they also have a blue one called the phycobilins.
They are also referred to as the blue green algae. They are important in the formation of the oxygen level in the earth’s atmosphere. They also help in several other attributes which are important to human life. They are microscopic and are found in several types of water bodies.
Just like the true algae and true example of prokaryotic cell they lack mitochondria, any membrane based nucleus and organelles. They obtain their own energy directly from the light source and get them converted into chemical for preparing their own food. This process is called photosynthesis.
Archaea
They are the group of cell that is single organism that is example of prokaryotic cell. These define the limits on earth.
Some of the examples of archaebacteria consists of the halophiles which are habitat of the salt surroundings, the methanogens that are the organism that produce methane and the thermophiles that can live in a very hot habitat.
They are organism that does not have a definite nucleus and are quite distant from the molecular characters that separate from the bacteria. Members of this group are Pyrolobus fumarii holding the upper temperature.
They had been discovered in the harsh conditions of nature like In the hot springs and the vents. They have their occurrence in the various ranges being acidic, saline and all the anaerobic situations.
The major part of archaea cannot be made in labs and the presence in the global areas has already been noticed via the use of many techniques that are culture independent.
Bacillus anthracis
They are the gram positive with being rod shape as an example of prokaryotic cell. they measure about 3 to 5 micron and have circular single DNA.
They cause up anthrax which is known to be a deadly disease for livestock and sometimes to humans as well. It is the only pathogen which is permanent along the Bacillus genus.
The discovery of this was the very first evidence in science for the germ theory of diseases. They are known to have 89 strains. Sterne strain is used in vaccines, vollum is isolated from cow.
Anthrax 836 is a high virulent strain by USSR. Ames strain are also siiolated from the cow and famous for Amerithrax attacks. H9401 is isolated from a Korean human patient using the anthrax vaccine.
It has some capsule which is a need for a full vaccine. It produces mostly there plasmid exotoxins. These can cause many infections and also can be treated with penicillin, ciprofloxacin and doxycycline.
Bacillus careus
They are the gram positive bacteria which are rod shaped and are anaerobic in nature.
These example of prokaryotic cell are motile also beta hemolytic and are known to form spore in the soil, aquatic sponges and food. The name cereus means “waxy” in Latin which means the visibility of colonies build on the blood agar.
These are said to produce toxin and are also said to be found in vegetation. It is said to cause diarrhea, vomiting and nausea. They are also associated with various infections in hosts and also are capable of causing septicemia.
These prokaryotic cells can lead to loss of vision and gastrointestinal illness. It is also associated with production of exo-enzymes that lead to destruction of tissue. They in the surrounding are ubiquitously an form spores allowinh them to survive long in harsh conditions as well.
Bacillus cereus is also caused by ingestion of contaminated food. Similar responses for the problem in respiratory tract have also been noticed in here for these bacteria.
Streptomyces soil bacterium
These are the bacteria from the family of actinomycetes and are the soil bacteria.
They are mostly in common in the family making up to 1 to 20% of the soil microbes that are cultured. The growth if its colony becomes more visible when there is a germination of spore and producing of filaments having many nuclei.
The filament of these bacteria elongates by the apical growth and branch out by continuous producing of mycelium that generated from both culture medium and inside it. There is also a formation of hyphae formed by the mycelium.
An approx. of all the natural antibiotics, two third of them and about almost 75% are from the Streptomyces genus. It has been sensed by Berdy that these generate about 7600 compounds that are bioactive in nature.
Most of these bacteria are either rhizoplane or rhizosphere colonizers. They can also be said to be endophytes that help colonize the within tissues of any host plants. These features of the example of prokaryotic cell make them a farmer favorite.
These hyphae penetrate from the medium in the visibility of the extracellular hydrolytic enzymes that mixes up the organic molecules that are present. They have filaments that allow them use the nutrients up to their efficiency and also enables colonization.
Escherichia coli bacteria
They are in general known as E.coli and are gram negative bacteria. They are the facultative anaerobic and are rod shaped.
Mostly these stains of prokaryotic cells are harmless and found mostly in the low intestine of all the warm blooded creatures. Some of the serotypes still can be the cause for food poisoning in the hosts.
They do play role in getting the food contaminated which prompt recalling of the product. The one that are not dangerous are part of all day microbut in the gut and benefits the host by generating of potassium.
These types are excelled out in the surrounding in the form of fecal matter. They grow mostly in fecal matter which are fresh under the aerobic conditions for about three days and decline slowly after the process.
Streotpcoccus bacteria
They are the compositions of the gram positive type of bacteria and are general example of prokaryotic cell.
The cell divisions in the streptococci takes place in the singular axis as they grow. They do tend to grow from chains or pairs that lead to getting it twisted. It is quite different from Staphylococci.
Thus for the reason they do not have a specific shape and form mostly clusters looking like grapes. Most of these are catalase negative and is oxidase negative with many also being factitive anaerobes.
They are of firmicutes phylum, class being bacilli. They are of order lactobacillales and the genus refers to streptococcus. They are also responsible or many cases like the bacterial pneumonia, pink eye, the endocarditis and endocarditis.
Moreover, mostly all the species are not pathogenic and thus form a part of human commensal microbiota in the skin, intestine and mouth. They are also an essential in generation of Emmentaler.
Lactobacillus acidophilus
The lactobacillus acodophilus are the ones which are located in the intestine. They do produce lactic acid and are thus given its name.
They are the members of genre Lacto bacillus and so play a role in human health. This is done by generating an enzyme known as lactase. They balance their way of being good and bad.
They help in balancing out quote of the harmful bacteria that shall not else flourish inside the gut for any antibiotic or illness. They are also used in getting the flora of that vagina balance and also prevent any generation of any infection.
They are mostly found in yogurt and many of the fermented food with also being and preferred in the form of supplement. They are mostly found in the non-pathogenesis organism and few of the strains are made in use as probiotics to get oneself prevention of some diseases.
Streptococcus pyogenes
They can be also termed as group A streptococcus (GAS) and are facultative gram positive bacteria that occur in chains.
They are also said to cause many more infections in the humans that consists of tonsillitis, scarlet fever, rheumatic fever, cellulitis, necrotizing fasciitis and pharyngitis.
They also can many diseases that can be life threatening just like bacteremia, myonecrosis, pneumonia and streptococcal toxic shock syndrome.
They are also a global vital human pathogen that helps in causing a large variety of infections that are acute in nature like the pharyngitis and many other infections in the soft tissue.
They can spread via any direct contact with nose discharge and throat. Sometimes they also spread via any infected and exposed wounds or via any sores on skin. The risk of it is high while a person is ill or has an infected wound.
Sulfolobus acidocaldarius archaebacterium
Sulfolobus are the genre of microbes which form in the family of Sulfolobaceae. It belongs to the domain of archaea.
Sulfolobus species do grow in the volcanic springs with an optimal temperature of 75 to 80 degree Celsius and a ph. level of 2 and 3. It helps making them thermophiles and acidophilus in general.
They are found in mostly in the Yellowstone national park’s that is rich in sulphur. They occur in very high temperature and also in high numbers getting it attached with the surface of any sulphur crystals.
Cell features of Prokaryotes
Some of the possession for the example of prokaryotic cell are-
- Ribosome- They is used during the process of protein synthesis.
- Nucleoid- It has the DNA and is the central area of the cell
- Cell membrane– All prokaryotes have a cell membrane which is also called the plasma membrane. They help the cell separate themselves from the outside world.
- Cytoplasm- they are the semi fluid inside the plasma membrane. The cell of the prokaryotes lack membrane covered organelles; they do contain some important features.
- Mesosomes– They are the extensions of plasma in the cell that from the tubules or the lamella.
- Glycocalyx– They are also called the slime layer and are mad eup of macromolecules and can be thick or loose.
- Cell wall- Just for the outside world, cell wall helps give protection and maintains the structure. Mostly all examples of prokaryotic cell have a cell wall that is rigid which is made of proteins known as the peptidoglycans and carbohydrates.
- Capsule- There are some bacteria that have in them a layer of carbohydrates which envelop the wall of cell and are called the capsule. This capsule helps the bacteria keep themselves attached with the surface.
- Fimbriae– they are the thin like structure also are same like hair which are used by the bacteria with their cellular attachment.
- Flagella– they are the tail like similar thin structures which help the organism in their movement. It has three parts, the filament, hook and the basal body.
- Pili- It is the rod shaped bodies which are involved in many roles that also incudes the transfer of DNA and cell attachment.
FAQs-
Do the prokaryotes have mitochondria?
No, they have no mitochondria. They are just found in eukaryotes.
What cell features are same to both the type of cell?
Some of the features similar to both are DNA, ribosomes, cytoplasm and plasma membrane.
What is the ribosome type in prokaryotes?
These have the ribosome which are 70s and are made up subunits that are of smaller 30s and larger 50s. They occur in the groups that are called polysomes.
What is the basic difference between eukaryotic and prokaryotic cell?
The basic difference lies in the fact that eukaryotic have a nucleus bounded with membrane but the prokaryotic ells do not.
Also Read:
- Example of density change
- Aufbau principle example
- Example of relative motion
- Genome example
- Transverse wave example
- Example of chemical change which is reversible
- Amplitude of a wave example
- Motion parallax example
- Constant angular velocity example
- Longitudinal wave example
I am Ankita Chattopadhyay from Kharagpur. I have completed my B. Tech in Biotechnology from Amity University Kolkata. I am a Subject Matter Expert in Biotechnology. I have been keen in writing articles and also interested in Literature with having my writing published in a Biotech website and a book respectively. Along with these, I am also a Hodophile, a Cinephile and a foodie.
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