Why mycoplasma is the smallest and simplest cell

From the perspective of the conditions necessary to ensure the operation of a cell's vital activities, the minimum limit diameter of a cell volume cannot be less than 100 nm, and the diameter of the smallest mycoplasma cell found now is close to this limit. Therefore, it seems impossible for cells that are smaller and simpler than mycoplasma to meet the basic requirements of life activities, so mycoplasma is the smallest and simplest cell.

Mycoplasma is a prokaryotic microorganism that resembles bacteria but does not have a cell wall, and is the smallest and simplest prokaryotic organism found so far, and it is also the smallest and simplest cell-type organism.

One is that mycoplasma cells have a simple structure, most of them are spherical, there is no cell wall, and there is only a three-layer cell membrane. The only organelles that are visible in a cell are ribosomes.

The second is very tiny, with a diameter of 50-300nm, which can pass through the bacterial filter.

Third, the mycoplasma genome is a circular double-stranded DNA with a small molecular weight (only one-fifth of that of Escherichia coli) and only 480 genes. And its DNA is scattered throughout the cell, and no nuclear region or nucleus is formed.

Fourth, there are only more than 100 kinds of enzymes in mycoplasma cells, and their synthesis and metabolism are very limited.

Scientists believe that mycoplasma cells are already the smallest limit of cellular organisms. No matter how small it is, the cell cannot contain the various components needed for cell growth and metabolism, such as DNA, RNA, proteins, lipids, etc., and cannot become a cell organism that grows independently.

Mycoplasma: Mycoplasma are the smallest organisms known to live freely and are also the smallest prokaryotic cells. It is a prokaryotic microorganism that is larger than viruses and smaller than bacteria, and they are distinguished by the absence of a cell wall.

As a result, the cells are soft, morphologically changeable, and highly pleomorphic. Observation of mycoplasma cells under electron microscopy shows that they have a cell membrane and ribosomes, RNA and circular DNA in the cellMycoplasma is widely found in soil, sewage, insects, vertebrates and humans, and is one of the pathogenic bacteria of animals, plants and humans.

Mycoplasma is another class of microscopic pathogens that differ from bacteria and fungi.

Chlamydia: Chlamydia is a widespread pathogen in nature. It is mostly globular and heap-shaped, with a cell wall, and is generally parasitic in animal cells.

Once classified as viruses, they were later found to be in their own right. It is a prokaryotic microorganism larger than viruses and smaller than bacteria, spherical in shape, only microns in diameter, it has no ability to move, chlamydia is widely parasitic in humans, mammals and birds, and only a few are pathogenic.