prokaryote


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prokaryote:

see MoneraMonera,
taxonomic kingdom that comprises the prokaryotes (bacteria and cyanobacteria). Prokaryotes are single-celled organisms that lack a membrane-bound nucleus and usually lack membrane-bound organelles (mitochondria, chloroplasts; see cell, in biology).
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Prokaryote

 

an organism that does not have a typical cell nucleus and chromosomal apparatus. Prokaryotes include bacteria, blue-green algae, rickettsiae, and mycoplasms.

In the organic world, according to the latest classification system, prokaryotes are classified as a kingdom (Prokariota) or a superkingdom that is comparable to the kingdom or super-kingdom of eukaryotes. In prokaryotes, the physical substrate associated with the transmission and realization of hereditary information consists of a strand of deoxyribonucleic acid (DNA). The DNA usually has a ringlike shape and is localized more or less in the central part of the organism, which is called the nucleoid; the nucleoid is not separated by a membrane from the cytoplasm. Unlike the DNA in eukaryotes, the DNA in prokaryotes is usually not bound to histones (it does not form nucleohistone) and the functioning of genes is regulated through metabolites. Also, prokaryotes do not have mitochondria and complexly organized flagella.

Prokaryotes play a very important role in the cycle of matter in the biosphere. Blue-green algae were probably the first autotrophic organisms to appear on earth in the course of the evolution of life.

REFERENCE

Peshkov, M. A. Tsitologiia bakterii. Moscow-Leningrad, 1955.

IU. I. POLIANSKII

prokaryote

[prō′kar·ē‚ōt]
(cell and molecular biology)
A primitive nucleus, where the deoxyribonucleic acid-containing region lacks a limiting membrane.
Any cell containing such a nucleus, such as the bacteria and the blue-green algae.
References in periodicals archive ?
CRISPR provides acquired resistance against viruses in prokaryotes. Science.
They infect a wide spectrum of hosts ranging from prokaryotes (e.g., bacteria and archaea) to unicellular and multicellular eukaryotes, and therefore are considered as a controlling factor of both the abundance and the genetic diversity of populations (Brussaard, 2004; Suttle, 2007; Fischer et at., 2010).
Lee et al., "Oligonucleotide microarray for 16S rRNA gene-based detection of all recognized lineages of sulfate-reducing prokaryotes in the environment," Applied and Environmental Microbiology, vol.
At present, however, we have only fragmentary knowledge even for the best-characterized model prokaryote E.
The isoprenoidal clade prokaryotes develop into other groups of prokaryotes via viroidal/virus as well as eukaryotic horizontal gene transfer producing bacterial speciation [25-27].
The ease with which bacteria have become resistant to a class of synthetic antibacterials is an example of the versatility of the prokaryotes.
For practical purposes prokaryote is still useful, says William "Barny" Whitman, a microbiologist at the University of Georgia in Athens.
photosynthetic prokaryote first described growing in association with
The early Archean "prokaryote" biota was only adapted to a world deficient in atmospheric oxygen.
In a preferred embodiment, the kinesins are produced from a prokaryote, most preferably, a bacterial cell.
During his first 10 years of effort at the University of Illinois, Woese gathered enough rRNA data on some 60 types of bacteria to begin publishing their genealogies--the shape of the prokaryote branch.