Prokaryotes

Prokaryotes

General Characteristics:

• Prokaryotes are unicellular organisms, which implies that they are composed of only a single cell.
• They are simple in their cellular organization, with no nucleus or other membrane-bound organelles within their cells.
• Their DNA is usually circular in shape, not bound within a nucleus, and is referred to as nucleoid.
• Prokaryotic cells are generally smaller in size as compared to eukaryotic cells.

Classification of Prokaryotes:

• Prokaryotes are mainly divided into two domains: Bacteria and Archaea.
• Bacteria are the most widely known prokaryotes and can be found in numerous diverse environments.
• Archaea are usually found in extreme environments, such as high temperatures or high salinity areas.

Reproduction in Prokaryotes:

• Prokaryotes reproduce asexually by a process known as binary fission, which is essentially cell division resulting in two identical cells.
• Some prokaryotes engage in a process known as conjugation, where DNA is transferred from one cell to another via a bridge-like structure formed between two cells. This process results in genetic variance among prokaryotes.

Metabolism and Growth:

• Prokaryotes have a broad range of metabolic abilities, which includes photosynthesis, fermentation, and nitrogen fixation.
• Growth in prokaryotes occurs in favourable conditions and can be extremely rapid, with some bacteria doubling in number every 20 minutes.

Role in the Ecosystem:

• Prokaryotes play crucial roles in recycling nutrients, such as carbon, nitrogen and sulphur in the ecosystem.
• They can also cause diseases in humans, animals, and plants, due to certain pathogenic strains.
• Many prokaryotes, especially bacteria, are used in industries for the production of foods like yoghurt and cheese, and in biotechnology and bioengineering for various purposes.